The carousel ballpoint pen

One Pen. Every Line.

For designers, architects and professionals who demand precision without compromise.

How it works

Built To Write

Slide to Select

01

Slide to Select

Slide to your line weight. Fine, medium, or bold, it clicks into place.

Toggle to Cap

02

Toggle to Cap

One press deploys the tip. One press retracts it. Pocket-safe every time.

Smooth Flow, Zero Wobble

03

Smooth Flow, Zero Wobble

±0.05mm precision. No wobble. Every line exactly as intended.

All colorways
Obsidian Black
Arctic White
Midnight Navy

All Colorways

Three Finishes. One Standard.

Obsidian Black, Arctic White, and Midnight Navy. Each with rose gold accents and the same precision carousel mechanism inside.

Obsidian Black

The Original. The Everyday Carry.

Matte black with rose gold accents. Stonewashed finish that develops character with every use.

Arctic White

Clean Lines. Bold Statement.

Glossy white with rose gold accents. High-contrast finish that stands out on any desk.

Midnight Navy

Refined. Confident. Considered.

Deep navy glossy with rose gold accents. Classic in the boardroom, precise on the drafting table.

Choose Your Build

Materials & Engineering

Every component chosen for a reason. Built to last a lifetime.

Body Material

Grade 5 Titanium

Ti-6Al-4V alloy, the same material used in aerospace and surgical instruments. Stronger than steel at half the weight. Develops a natural patina with use that makes each pen unique.

  • 3-5x stronger than aluminum
  • Corrosion and scratch resistant
  • Hypoallergenic, safe for all skin types
  • Stonewashed or brushed satin finish

Mechanism Housing

316L Stainless Steel

The internal carousel disc and deployment rail are machined from surgical-grade stainless steel for maximum wear resistance across 10,000+ switching cycles.

Accents & Clip

Rose Gold PVD

Physical vapor deposition coating on all accent hardware. More durable than plating won't chip, peel, or fade under daily carry conditions.

Grip Zone

Machined Micro-Knurl

CNC-machined crosshatch texture directly into the titanium barrel. No rubber, no inserts, pure metal grip that improves with wear.

Body Material

6061-T6 Aluminum

Aircraft-grade aluminum alloy. Lightweight, precise, and anodized for a clean durable finish. The ideal entry point into the Senkō experience without compromising the mechanism quality.

  • Significantly lighter than titanium
  • Hard anodized finish for scratch resistance
  • Available in additional color options
  • Same internal mechanism as titanium model

Mechanism Housing

316L Stainless Steel

Identical internal components to the titanium model. The carousel, detent springs, and deployment rail are all stainless steel regardless of body material.

Accents & Clip

Rose Gold PVD

Same rose gold PVD hardware as the titanium model. Consistent premium finish across both material options.

Grip Zone

Machined Micro-Knurl

CNC-machined crosshatch texture anodized into the aluminum barrel. Lightweight feel with confident grip, ideal for extended writing sessions.

Early reactions

What people are saying.

“I mark up blueprints with three different weights throughout the day. The idea of one pen that handles all of that without me reaching into my bag every five minutes, I reserved immediately. Can't get here fast enough.”

Jamie R.

Construction Manager, Seattle

“Every design review I'm switching between annotating, sketching, and signing off on things. I've been waiting for something like this for years. The carousel mechanism alone sold me, I put my spot down without hesitation.”

Robert N.

Product Designer, New York

“I carry two pens on every site visit and I've lost count of how many times I've lost one. The second I saw what Senkō was doing I reserved. The fact that it's titanium and built to last makes it even better.”

Natalie J.

Architect Student, Boston

Questions

Everything you want to know.

Most multi-pens are plastic, feel cheap, and switch between ink colors, not line weights. Senkō uses a precision slider that rotates an internal carousel to select between fine (0.5mm), medium (0.7mm), and bold (1.0mm) ballpoint tips. Toggle the cap to lock it in and write. No disassembly, no fumbling.

Slide the selector on the barrel to your desired tip weight, 0.5mm, 0.7mm, or 1.0mm. The slider rotates the internal carousel and clicks into position so you know exactly which tip is active. Then toggle the cap down to deploy and lock the tip. The whole process takes under 3 seconds, one-handed.

The carousel switching mechanism is rated to 10,000+ cycles without precision loss. If it ever fails under normal use, we will make it right.

Senkō is approximately 140mm in length and 13.5mm in diameter at the grip, weighing between 28–35 grams, comparable to the rOtring 800 and perfectly balanced for long writing sessions.

Senkō is compatible with Schmidt and Parker-style ballpoint refills.