Works with Arcturus Karambit and Arcturus AR03. Pictured beside original short battery cap. Gives you almost double the battery space while still letting you use the original stock. Made out of carbon fiber ABS. Polycarbonate option available for 5$ more. If you are interested in anything else 3d printed send me a message. I think I am the only person on Hopup offering carbon fiber polycarbonate 3d prints. Have a print job that needs true durability? Contact me today or visit my website/ e-shop to learn more. https://www.cedar3d.com/