This is a magazine extension that increases the magazine capacity from 5 to 7 rounds and also allows a round in the chamber with 7 in the magazine. These are made from chopped carbon fiber filament in a specialized 3D printing process, the adapters are equal in strength to aluminum with increased flexibility to withstand stress without damage. These have been tested with the old style magazine and the new magazine with the small spring and both worked flawlessly.

Byrna HD Magazine extension