---
product_id: 63160131
title: "Uni-ball Signo RT1 Retractable Gel Ink Pen, Ultra Micro Point 0.28mm, Rubber Grip, UMN-155-28, 10 Color Value Set"
brand: "uni-ball"
price: "¥4120"
currency: JPY
in_stock: true
category: "Uni Ball"
url: https://www.desertcart.jp/products/63160131-uni-ball-signo-rt1-retractable-gel-ink-pen-ultra-micro
store_origin: JP
region: Japan
---

# Ergonomic rubber grip for comfort 10 vibrant gel ink colors 0.28mm Ultra Micro Point for precision Uni-ball Signo RT1 Retractable Gel Ink Pen, Ultra Micro Point 0.28mm, Rubber Grip, UMN-155-28, 10 Color Value Set

**Brand:** uni-ball
**Price:** ¥4120
**Availability:** ✅ In Stock

## Summary

> 🖋️ Write sharp, stand out sharper.

## Quick Answers

- **What is this?** Uni-ball Signo RT1 Retractable Gel Ink Pen, Ultra Micro Point 0.28mm, Rubber Grip, UMN-155-28, 10 Color Value Set by uni-ball
- **How much does it cost?** ¥4120 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.jp](https://www.desertcart.jp/products/63160131-uni-ball-signo-rt1-retractable-gel-ink-pen-ultra-micro)

## Best For

- uni-ball enthusiasts

## Why This Product

- Trusted uni-ball brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Pinpoint Precision:** Ultra micro 0.28mm tip delivers crisp, clean lines for flawless notes and sketches.
- • **Comfort Meets Control:** Soft rubber grip ensures fatigue-free writing during long meetings or brainstorming sessions.
- • **Retractable Convenience:** Smooth retractable design keeps your pen protected and ready to go—no cap, no hassle.
- • **Vibrant 10-Color Palette:** Express your creativity or organize your work with a spectrum of bold, fade-resistant gel inks.
- • **Trusted Quality & Popularity:** Highly rated with 4.6 stars and a top 510 rank in gel pens—join thousands who trust Uni-ball.

## Overview

The Uni-ball Signo RT1 is a premium retractable gel ink pen featuring an ultra micro 0.28mm tip for precise writing, a comfortable rubber grip, and a vibrant 10-color set designed for professionals who demand both style and performance in their everyday writing tools.

## Description

Uni-ball Signo RT1 Retractable Gel Ink Pen, Ultra Micro Point 0.28mm, UMN-155-28, 10 Color Value Set

## Features

- Smooth and easy to write
- 10 Color Set: black, red, blue, baby pink, orange, lime green, green, light blue, blue black, violet.
- Uni-ball Signo RT1 Retractable Gel Ink Pen, UMN-155-28
- Ultra Micro Point 0.28mm

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B01N6ZE42N |
| Additional Features | Retractable |
| Age Range Description | Adult |
| Best Sellers Rank | #21,189 in Office Products ( See Top 100 in Office Products ) #510 in Gel Ink Pens |
| Body Shape | Round |
| Brand Name | Uni-Ball |
| Closure Type | Retractable |
| Color | Black,Blue,Green,Orange,Violet |
| Customer Reviews | 4.6 4.6 out of 5 stars (938) |
| Drill Point | Ultra Micro |
| Grip Type | Rubber |
| Hand Orientation | Ambidextrous |
| Included Components | 10 Uni-ball Signo RT1 Retractable Gel Ink Pens |
| Ink Base | Water |
| Ink Color | Black,Blue,Orange,Pink,Red |
| Item Diameter | 0.28 millimeters |
| Item Dimensions | 5.55 x 4.33 x 0.79 inches |
| Line Size | 0_3mm |
| Manufacturer | Uni-ball |
| Material Type | Rubber |
| Model Name | SG_B01N6ZE42N_US |
| Model Number | SG_B01N6ZE42N_US |
| Recommended Uses For Product | Writing |
| Style | Pen |
| UPC | 191308004132 |
| Unit Count | 10 Count |
| Writing Instrument Form | Ballpoint Pen |
| Writing Technique | gel ink |

## Product Details

- **Age Range (Description):** Adult
- **Brand:** Uni-Ball
- **Color:** Black,Blue,Green,Orange,Violet
- **Ink Color:** Black,Blue,Orange,Pink,Red
- **Writing Instrument Form:** Ballpoint Pen

## Images

![Uni-ball Signo RT1 Retractable Gel Ink Pen, Ultra Micro Point 0.28mm, Rubber Grip, UMN-155-28, 10 Color Value Set - Image 1](https://m.media-amazon.com/images/I/71WrPPU+KPL.jpg)

## Questions & Answers

**Q: Do these bleed through on Bible pages?**
A: I don't know the answer to that, but I wouldn't even TRY them in my bible (and I'm a Bible journaler!). I use prismacolor colored pencils in all my Bibles.

**Q: Where can I buy refills for this pen?**
A: You should be able to purchase refills here on Amazon

**Q: Can you right on a rock with these?**
A: I have not tried to do so, and I really doubt that fine of tip would  work very well. I guess I would experiment to see if you could. They do make pens especially for writing and painting on rock. I would recommend that type of pen, but try these to see.

**Q: Has anyone colored with these?**
A: My uni ball Signo RT1 collection of color gel pens are of 0.28 mm fineness. They are very 
very fine point. At such fine point, I think you
can only write with it. I think it will be hard to
color anything with it.

## Frequently Bought Together

- Uni-ball Signo RT1 Retractable Gel Ink Pen, Ultra Micro Point 0.28mm, Rubber Grip, UMN-155-28, 10 Color Value Set
- Uni-ball Signo RT1 Retractable Gel Ink Pen, Ultra Micro Point 0.28mm, Rubber Grip, Black Ink, UMN-155-28, Value Set of 5
- UPENOTE Gel Pens 0.28mm Extra Fine Point Pen, Black Ink, Ball Point Pen for School, Office, Stationery Supplies 6 Packs

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**Shop now:** [https://www.desertcart.jp/products/63160131-uni-ball-signo-rt1-retractable-gel-ink-pen-ultra-micro](https://www.desertcart.jp/products/63160131-uni-ball-signo-rt1-retractable-gel-ink-pen-ultra-micro)

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*Product available on Desertcart Japan*
*Store origin: JP*
*Last updated: 2026-09-09*