Cartesian Ring
Walnut/Carbon
Striking carbon meets genuine walnut — innovation and nature united in every Cartesian Ring.
Made from genuine natural materials, with unique variations in color and texture.
Free shipping including trackingOur customers benefit from free and fast shipping. More information here >
24-month warrantyDuring the first 24 months, we take care of any issues that arise through normal use. Learn more >
Free returns till January 31, 2027 | Club AccountSo you can shop for your Christmas gifts with no risk at all, we’re extending our return period until January 31, 2027. Club membership is 100% free—members receive a prepaid return label at no additional cost. Even without an account, you can return items until January 31, 2027; a small label fee applies.
Packaged as a gift?
Description
The visual representation in the coordinate system is a good aid for complex mathematical problems and turns confusing puzzles into solvable challenges.
Stay on top of any challenge with your "Cartesian" ring! The combination of warm walnut wood, carbon fibre and stainless steel is guaranteed to be waterproof and is the perfect complement to any outfit. With your "Cartesian" you'll surely be ready for any challenge you may face in life!
Details
What's included
Your model
Storage box
Cork holder
Protective packaging
Find your perfect ring size
Enter your finger circumference or the inner diameter of a ring that fits to calculate your ring size.
Please check your input.
Find your perfect ring size
Your ring size is:
This model is currently unavailable in your size.
Find your perfect ring size
The measurement you entered differs significantly from our standard sizes. Please measure again using our instructions.
Here's how to find your finger circumference in a few steps:
You need:
- A piece of paper or string
- A pen
- A ruler
-
Step 1
Wrap a narrow strip of paper or string around the part of the finger where the ring will sit.
-
Step 2
Mark the point where the paper overlaps with a fine pen.
-
Step 3
Measure the distance to the mark with a ruler in millimetres (mm).
Pro tip: Fingers are usually slightly wider in the evening. Measure at the end of the day for maximum comfort.
Measure the inner diameter
You need:
- A piece of paper or string
- A pen
- A ruler
-
Step 1
Place the ring on a ruler.
-
Step 2
Measure the inner diameter from one side to the other.
-
Step 3
Round the result to the nearest millimetre.
Core features
Where nature meets craftsmanship
Before it is packaged and shipped, each piece is individually inspected to ensure that it truly meets our high quality standards.
If it passes the test, we’ll package it carefully, securely, and as plastic-free as possible. We include tools and replacement links with watches and Bandlets so you can adjust your product to your size right away at home.
Just a few days later, you’ll be thrilled to find your package waiting on your doorstep! Unpack it quickly and try it on—you can test your items for 24 days and simply send them back if you don’t like them.
If you have any questions or issues, you can reach us through our service form. No waiting on hold or automated responses—our customer support team consists of 15 employees who are always committed to ensuring your satisfaction.
“With Holzkern I always want to express my love for nature and have set myself the goal of creating the perfect piece of nature for everyone.”
