Erasable Frixion Ball Knock Zone vs Uni-ball R:E 0.5mm
Buy the Pilot Erasable Frixion Ball Knock Zone if you want the darker, longer-lasting erasable ink and a quieter, more solid-feeling pen; it costs $4.55 at Kiichin as of November 3, 2026. Buy the Uni-ball R:E 0.5mm if you want the lowest price on a fine-point erasable gel pen; it costs $3.40 at kawaiizaki.com as of November 3, 2026. The gap is about $1.15, so the Pilot's ink and build upgrades are cheap if you write often.
Today the Uni-ball R:E 0.5mm costs $1.15 less at its best price.
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Erasable Frixion Ball Knock Zone
5$4.55at KiichinObserved at 6:34 AM
Choose the Pilot Frixion Ball Knock Zone if you want darker erasable ink, a bigger refill, a quieter click and a rubber grip for long writing sessions.
Pros
- Premium black ink is 70% deeper than original Frixion ink.
- Refill holds 70% more ink, so fewer changes.
- Quieter knock and a stabilizing tip holder reduce rattle.
- Rubber grip and refillable eraser.
- Refills come in a 2-pack with all three ink colors.
Cons
- Costs about $1.15 more than the Uni-ball R:E.
- Ink is smooth but less saturated than regular gel pens.
What separates them
| Erasable Frixion Ball Knock Zone | Uni-ball R:E 0.5mm | |
|---|---|---|
| Price (new, November 3, 2026) | $4.55 at Kiichin | $3.40 at kawaiizaki.com |
| Tip size | 0.5 mm conical, metal | 0.5 mm extra fine |
| Erasable ink | Yes, water-based gel; premium black is 70% deeper than original Frixion ink | Yes, erasable gel |
| Refill capacity | Premium refill holds 70% more ink than original Frixion refills | Refillable, capacity not specified |
| Grip | Rubber grip, 9.7 mm diameter | Not specified |
| Retractable | Yes, slide button with quieter knock mechanism | Not specified |
| Weight | 15 g / 0.51 oz | Not specified |
| Eraser replacement |
Price history
- Erasable Frixion Ball Knock Zone: lowest $4.55 on Nov 3 at Kiichin.
- Uni-ball R:E 0.5mm: lowest $3.40 on Nov 3 at Tokyo Pen Shop.
Prices at every store
Erasable Frixion Ball Knock Zone
- Yoseka StationeryNew
In stock
$6.50Free shippingObserved at 6:34 AM - KiichinNew
Availability unknown
$4.55Observed at 6:34 AM - CHL StoreNew
Availability unknown
$4.69Observed at 6:34 AM - AmazonNew
Availability unknown
$8.00Observed at 6:03 AM
Also available at
- KAWAIIZAKICheck price at KAWAIIZAKI
- Tokyo Pen ShopCheck price at Tokyo Pen Shop
Specs compared
| Spec | Erasable Frixion Ball Knock Zone | Uni-ball R:E 0.5mm |
|---|---|---|
| Ink Color | Black | Black Ink |
| Tip Size | 0.5 mm | — |
| Tip Type | Conical | — |
| Tip Material | Metal | — |
| Length Retracted | 15.0 cm / 5.9 inches | — |
| Weight | 0.51 oz / 15 grams | — |
| Max Diameter | 10.9 mm | — |
| Grip Diameter | 9.7 mm | — |
| Body Material | Plastic | — |
| Grip Material | Rubber | — |
| Retractable | Retractable - Slide Button |
Questions and answers
- Which is better for everyday note-taking?
- The Pilot Frixion Ball Knock Zone. Its rubber grip, quieter click and 70% larger refill suit long sessions. The Uni-ball R:E works fine if you want to spend less.
- Is the Pilot worth the extra $1.15?
- Yes if you write a lot. The darker premium ink and 70% bigger refill cut refill changes, and the grip and quieter knock are real upgrades. If you barely use an eraser pen, save the money.
- Which has darker erasable ink?
- The Pilot. Its premium black ink is 70% deeper than original Frixion ink, and buyers call it darker than other Frixion pens. Uni-ball does not publish a comparable figure for the R:E.
- Which lasts longer before a refill?
- The Pilot, by its own spec: the premium refill holds 70% more ink than original Frixion refills. Uni-ball does not state refill capacity for the R:E.
- Do both have a 0.5 mm tip?
- Yes. Both are 0.5 mm fine-point erasable gel pens in black. The Pilot uses a conical metal tip; Uni-ball lists the R:E as extra fine.
- Can I replace the eraser?
- On the Pilot, yes: a Frixion Ball Knock Zone eraser replacement is sold separately. Uni-ball does not list an eraser refill for the R:E.