--- title: "uni Propus Window: The Highlighter With a See-Through Tip" canonical: "https://stationerytimes.com/guides/uni-propus-window-highlighter/" description: "uni Propus Window highlighter explained: the windowed 4.0 mm chisel, the 0.6 mm fine end, Q-Dry quick-dry ink, soft colors, sizes, Japan prices and origin." category: "Pens" type: "Highlighter" published: 2026-10-22 updated: 2026-10-24 author: "Ellis Penhale" publisher: "Stationery Times" sources: 8 products: - name: "uni Propus Window double-ended highlighter (PUS-102T)" brand: "uni" brand_origin: "Japan" made_in: "Not stated" material: "Plastic barrel and caps; felt chisel with a clear window and felt fine tip; water-based ink (Mitsubishi Pencil, Amazon)" released: "2000" price_band: "$ (under $5 per pen (multi-packs divided by the count), typical US retail, October 2026)" manufacturer: "Mitsubishi Pencil Co., Ltd. (Tokyo)" model: "Propus Window PUS-102T" mpn: "PUS102T5C" gtin: "4902778692417" url: "https://www.mpuni.co.jp/products/felt_tip_pens/marker/propus/window/pus_102t.html" --- # uni Propus Window: The Highlighter With a See-Through Tip > The uni Propus Window is a double-ended Japanese highlighter from Mitsubishi Pencil with a clear window in its 4.0 mm chisel, so you can see the text and stop exactly where you want. The other end is a 0.6 mm fine tip. Launched in 2000, it costs ¥132 (about US$0.80) in Japan and sits in our $ band. - URL: https://stationerytimes.com/guides/uni-propus-window-highlighter/ - Category: Pens - Author: Ellis Penhale - Published: 2026-10-22 - Updated: 2026-10-24 ![Pink uni Propus Window double-ended highlighter drawn to scale at 138 mm capped, with a close-up of the window in its chisel tip](https://stationerytimes.com/images/raster/uni-propus-window-highlighter-16x9.png) *The Propus Window, 138 mm capped; the window in the chisel shows the text underneath.* Original drawing (SVG): . Drawings © 2026 Stationery Times, reusable with credit under CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). ## Product facts | Product | Brand | Brand origin | Made in | Material | Released | Price range (typical US retail, October 2026) | |---|---|---|---|---|---|---| | uni Propus Window double-ended highlighter (PUS-102T) | uni (by Mitsubishi Pencil Co., Ltd. (Tokyo)) | Japan | Not stated | Plastic barrel and caps; felt chisel with a clear window and felt fine tip; water-based ink (Mitsubishi Pencil, Amazon) | 2000 | $: under $5 per pen (multi-packs divided by the count) | - Made in (uni Propus Window double-ended highlighter (PUS-102T)): Not stated. Mitsubishi Pencil's Japanese Propus Window pages and press releases (read on October 22, 2026), JetPens and Amazon US don't state a country of manufacture. Check the barrel or package. ### uni Propus Window double-ended highlighter (PUS-102T) colors - Ink colors (5 standard, 0 special edition): Pink; Yellow; Orange; Green; Sky Blue. - Per Mitsubishi Pencil Japan (https://www.mpuni.co.jp/products/felt_tip_pens/marker/propus/window/pus_102t.html), checked 2026-10-24. The five PUS-102T colors on Mitsubishi Pencil Japan's page (桃, 黄, 橙, 緑, 空色), translated. The 2011 Soft Colors and the PUS-103T color markers have their own codes and aren't listed. Tints were sampled from Mitsubishi Pencil's product photos. Shops stock different colors; check the listing. ## Key takeaways - The broad end is a 4.0 mm chisel with a window cut into the tip, and the fine end draws 0.6 mm (Mitsubishi Pencil). - Mitsubishi Pencil launched the Propus Window in 2000 and added five pastel Soft Colors on February 16, 2011. - The Q-Dry version, out October 30, 2015, dries in under a third of the time of uni's earlier ink, per the maker. - JetPens lists the Q-Dry at 138 mm (5.4 in) capped, 11.5 mm across and about 8 g. - Mitsubishi Pencil's Japanese list price is ¥132 (about US$0.80) a pen, or ¥660 (about US$4.20) for five. ## What is the uni Propus Window? **It's a double-ended highlighter from Mitsubishi Pencil (uni) with a clear window in the broad chisel tip, so the text stays visible while you mark it.** Mitsubishi Pencil sells it with the promise that lines don't run past the words you meant to highlight. The company says the Propus Window went on sale in 2000 and became a favorite with students. JetPens picks the quick-drying version as its best highlighter for left-handed writers, and on Amazon US the five-color PUS-102T set had 1,609 ratings on October 22, 2026. ## uni Propus Window specs | Spec | Value | |---|---| | Maker | Mitsubishi Pencil Co., Ltd., Tokyo | | Model | PUS-102T (standard); PUS-103T (color markers); Q-Dry version | | Broad tip | 4.0 mm chisel with a window (Mitsubishi Pencil) | | Fine tip | 0.6 mm (PUS-102T); 0.4 mm plastic tip (PUS-103T) | | Ink | Water-based (Amazon) | | Length | 138 mm (5.4 in) capped, 120 mm (4.7 in) uncapped (JetPens, Q-Dry) | | Diameter | 11.5 mm (0.45 in) max (JetPens) | | Weight | About 8 g with ink (JetPens) | | Japan list price | ¥132 (about US$0.80) each, with tax | | Price band | $ (under $5 per pen) | | Made in | Not stated | ![uni Propus Window tip widths drawn to scale: 4.0 mm windowed chisel, 0.6 mm fine tip and 0.4 mm fine tip](https://stationerytimes.com/images/uni-propus-window-highlighter-tips.svg) *The three Propus Window line widths Mitsubishi Pencil publishes, magnified.* ## How does the window in the tip work? **A clear section is molded into the felt chisel, so the printed letters show through it as you draw.** With an ordinary chisel, the tip hides the end of the word, and most people overshoot. Mitsubishi Pencil says the window lets you mark only the part you want to check. The window is on the broad end only; the 0.6 mm fine end is a plain felt tip for underlining or writing small notes. ## What is the Propus Window Q-Dry? **It's the quick-drying version, launched on October 30, 2015, with what uni calls Q-Dry ink.** Mitsubishi Pencil says the ink dries in under a third of the time of its earlier highlighter ink, so it doesn't smear on coated textbook pages or your hand. At launch, uni listed it at ¥130 (about US$0.80) before tax in sky blue, green, yellow, orange and pink, plus yellow and pink in a black barrel. Uni says the colored particles still fix firmly to the paper, so the line resists rubbing. ## Which Propus Window colors are there? **Five standard fluorescent colors, five pastel Soft Colors and fifteen color-marker shades.** The standard PUS-102T comes in pink, yellow, orange, green and sky blue. | Line | Colors | Fine tip | |---|---|---| | Standard PUS-102T | Pink, yellow, orange, green, sky blue | 0.6 mm | | Soft Color (2011) | Yamabuki, lime, aqua, lavender, sakura | 0.6 mm | | Color marker PUS-103T (2019) | 5 basic, 5 light, 5 smoke | 0.4 mm | The 2019 color markers swapped the felt fine tip for a 0.4 mm plastic one that Mitsubishi Pencil says suits writing words, not only underlining. ## How does it compare with other highlighters? **It's the pick when you need to stop exactly at a word; pastel and refillable highlighters win on other things.** The [Zebra Mildliner](https://stationerytimes.com/guides/zebra-mildliner/) has softer colors and a bullet fine end, while the [Monami Essenti Soft](https://stationerytimes.com/guides/monami-essenti-soft-highlighter/) is a slimmer single-tip pastel. For notes written in water-based gel ink, the [Zebra Justfit Mojini Line](https://stationerytimes.com/guides/zebra-justfit-mojini-line/) is built not to smear the ink. All three sit in our $ band. ## Where is the uni Propus Window made? **Mitsubishi Pencil doesn't say on the pages we read, and neither do JetPens or Amazon US.** The brand is Japanese: uni is Mitsubishi Pencil's brand, based in Tokyo. Check the barrel or package if the country of manufacture matters to you. ## Frequently asked questions ### Why does the Propus Window have a hole in the tip? It's a clear window molded into the chisel. Mitsubishi Pencil says you can see the letters through it while you draw, so the line doesn't run past the words you want to mark. ### What tip sizes does the uni Propus Window have? The broad end is a 4.0 mm windowed chisel. The fine end is 0.6 mm on the standard PUS-102T and 0.4 mm on the PUS-103T color markers launched in 2019. ### Is the Propus Window good for left-handed people? The Q-Dry version is JetPens' pick for left-handed writers, because Mitsubishi Pencil says its ink dries in under a third of the time of its earlier highlighter ink, so a trailing hand smears it less. ### What are the Propus Window Soft Colors? Five pastel shades Mitsubishi Pencil added on February 16, 2011: yamabuki (golden yellow), lime, aqua, lavender and sakura pink. ### How much is a Propus Window in Japan? Mitsubishi Pencil lists ¥132 (about US$0.80) with tax for one pen, ¥396 (about US$2.50) for three colors and ¥660 (about US$4.20) for five. ### Is the uni Propus Window made in the USA? No. It's a Japanese uni product; neither Mitsubishi Pencil nor the US retailers we checked state the factory country. ## Sources - [三菱鉛筆: プロパス・ウインドウ PUS-102T (Mitsubishi Pencil Japan product page: colors, ¥132 each, ¥396 3-color, ¥660 5-color, JAN 4902778692417 for PUS-102T 5C; read October 22, 2026)](https://www.mpuni.co.jp/products/felt_tip_pens/marker/propus/window/pus_102t.html) - [三菱鉛筆: プロパス・ウインドウ シリーズ (series page: window in the tip, lines don't run over)](https://www.mpuni.co.jp/products/felt_tip_pens/marker/propus/window.html) - [三菱鉛筆 プレスリリース: 『プロパス・ウインドウ ソフトカラー』 (January 26, 2011: on sale February 16, 2011, 5 pastel colors, 4.0/0.6 mm, launched 2000)](https://www.mpuni.co.jp/company/press/20110126-37059.html) - [三菱鉛筆 プレスリリース: 『プロパス ウインドウ クイックドライ』 (October 19, 2015: Q-Dry ink dries in under a third of the time, on sale October 30, 2015, 7 versions)](https://www.mpuni.co.jp/company/press/20151019-36855.html) - [三菱鉛筆 プレスルーム: 『プロパス・ウインドウ』シリーズ カラーマーカー (September 20, 2019: PUS-103T, 15 colors, 4.0/0.4 mm, on sale October 25, 2019)](https://www.mpuni.co.jp/pressroom/20190920-36577.html) - [JetPens: Uni Propus Window Q-Dry Double-Sided Highlighter, 5 Color Set #1 (13.8 cm capped, 11.5 mm max, about 8 g)](https://www.jetpens.com/Uni-Propus-Window-Q-Dry-Double-Sided-Highlighter-4.0-mm-0.6-mm-5-Color-Set-1/pd/15065) - [JetPens: The Best Highlighter Pens (Propus Window Q-Dry picked for left-handed writers)](https://www.jetpens.com/blog/The-Best-Highlighter-Pens/pt/606) - [Amazon US: Uni Propus Window double-sided highlighter, 5 color set PUS102T5C (GTIN 04902778692417; 1,609 ratings on October 22, 2026)](https://www.amazon.com/dp/B001MTFYAY)