First a little explanation: Subitus means impromptu in Latin. Karambits are a type of Indonesian martial arts knife.

Disclaimer: Karambits are very dangerous and (quality) utility knife blades are razor sharp. Even if you are an experienced karambit flipper be very careful as this is likely to flip differently, is differently balanced, and much lighter. This may be illegal to carry in some countries. Ask your guardian for permission before printing if under 18 years old.

This karambit is designed to be as lightweight and minimalist as possible and requires only superglue and a single utility knife blade to assemble. It features a hexagon textured handle for improved grip and aesthetic, an ergonomic unibody design, and a large ring for easier spinning and thumb use. As the cutting element it uses one standard 60mm utility knife blade available dirt cheap from any hardware store.

A sheath is included as well and is specially designed to be no thicker than the knife handle it's self (a feature that I believe to be entirely unique) while still securely locking in place and being easy to remove one handed. It also has strap cutter notch and a slotted 7mm lanyard hole.

update 1/15/22: Added pocketclip/belt clip that snaps onto sheath (glue on for permanent use). You can mirror the clip for left handed use or for in pocket carry (recommended).

Update: 2/11/22. Evidently this model (and most others on the front page) are being scraped and sold on Etsy. (Not 3d print's just the models). This is liscencd as non commercial and I have not and will not give anyone permission to sell this 3d model. I may be willing to let someone sell prints of it under pre-determined terms with credit.

Update 3/30/22:
https://www.etsy.com/listing/1181202225/karimbit-utility-razor-knife
This seller is selling prints of a remix with replaceable blade's. If you don't own a 3d printer and want one of these they may be a good option.