ZEV Technologies Professional Plus Mag-well has an aluminum one piece design with a matte black, smooth anodized finish. The mag-well is slightly flared at the base which makes it ideal for quickly inserting the magazine in the pistol during reloads. It comes with one magwell body, mounting screw, and allen wrench. This model is compatible with Glock 17/17C/17L/22/22C/24/24C/31/31C/34/35/37 Gen 1-4 standard and compact. It does not work with 10-round magazines and Gen4 backstraps may need to be modified if used.