uni Jetstream Prime 2&1 Multi-Function Pen Review: A Brass Body Pen That Finally Got It Right

Introduction

The uni Jetstream Prime 2&1 is a multi-function pen that launched on January 26, 2022, priced at 3,630 yen. It pairs 0.5mm black and red ballpoint refills with a 0.5mm mechanical pencil, all inside a slim brass-bodied barrel that also comes in limited-edition Coral Pink and Smoky Green colorways alongside the standard Black and Beige finishes.

This review focuses on the Beige version, compared alongside the Black model from the same Prime series. The big question: does the improved knock mechanism hold up in daily use?

Design and Build Quality

Visually, the 2&1 shares its design with the Prime 3-color ballpoint released in 2021, which was offered in Black and Beige. The barrel and grip are made of brass, while the knock section and clip are finished in black for a unified, understated look. On the Black model the barrel is matte, whereas the Beige has a glossy coating that is surprisingly resistant to slipping. The knock top is black rather than colored, which gives the pen a cleaner, more premium appearance.

The Beige finish feels smooth with just a slight bit of grip under the fingers, which makes the pen easier to hold securely than the slicker Black version. The clip is easy to use and well made. Printing on the barrel is minimal and discreet, placed so it does not detract from the design.

One thing to know before buying: despite the built-in mechanical pencil, there is no eraser in the knock section. If you rely on an eraser, plan accordingly. The rear knock button protrudes slightly more than the two side buttons because it doubles as the pencil advance, which also makes it easier to knock. The center of gravity sits low, close to the middle.

Specifications at a Glance

The core specs are straightforward. Total length is 143mm, weight is 26.3g, and the shaft diameter is 11mm. The refill is a D1-type Jetstream SXR-2005 metal refill available in multiple colors. Both the ballpoints run at 0.5mm, and the pencil is 0.5mm as well.

How It Writes

In black ink, the Beige barrel offers noticeably better grip than the Black, giving very stable handwriting with minimal tip wobble. The red ink is equally smooth and pleasant to write with.

The mechanical pencil is the interesting one. It has less tip wobble and is easy to use, but it writes with a slightly soft, floating feel rather than the crisp, tapping sensation of a typical mechanical pencil. It takes a little getting used to, but once you adapt, it is easy to draw and write with. Despite the pencil mechanism, the whole package sits in a surprisingly slim barrel, which makes it comfortable to hold without feeling bulky.

The Knock Mechanism: The Big Improvement

The new knock mechanism is the headline change here. The buttons do not sink into the barrel when pressed, and this version was promised to have improved durability over the earlier 3-color model. After use, the improvement is real: switching functions is noticeably smoother, and the added strength presumably comes from reinforcing the knock assembly to handle the pencil mechanism.

There is a small learning curve because you knock the buttons at the top rather than pressing the usual side parts, but it is not a real problem in practice. The remaining question is long-term durability, which only extended use will answer, but out of the box this feels like a genuinely refined mechanism.

Refills and Everyday Practicality

The pen uses D1-type Jetstream SXR-2005 metal refills in each color, which keeps the writing character consistent with other Jetstream pens. The combination of two 0.5mm ballpoints and a pencil in a slim 11mm barrel makes this a practical daily-carry option for people who want one pen instead of three.

If you rarely use a mechanical pencil, the earlier 3-color ballpoint may suit you better. But if you want the pencil in the same body, this is the version to get, and the limited Coral Pink and Smoky Green colors are worth a look if you prefer something more playful than Black or Beige.

Buying Advice

The Beige finish is the standout choice for grip and feel, while the Black suits those who prefer a fully matte look. Buyers who use erasers frequently should note the pencil has none built in, and anyone who dislikes the soft pencil feel should test expectations accordingly.

At 3,630 yen, this sits in the upper range of mainstream multi-function pens, justified by the brass construction, the refined knock mechanism, and the clean design. If you have been waiting for the Prime series to add a pencil without compromise, this is the version that finally delivers.

Conclusion

The uni Jetstream Prime 2&1 takes what made the 3-color Prime appealing and adds a mechanical pencil with a genuinely improved, smoother knock mechanism. With comfortable brass construction, stable writing, and attractive color options, it earns a confident recommendation for anyone in the market for a well-made multi-function pen.