Die Free Co Dos Boot 3 Pack Black Dos Boot - Magpul PMAG Gen M3 - a low-profile base plate upgrade for Gen M3-pattern AR15/M4 magazines. It adds +2 rounds of capacity, improves grip for faster reloads, and provides added stability when used as a monopod. Designed around 20-round magazines, the Dos Boot keeps your setup low in prone positions while helping prevent the rifle grip from contacting dirt. Its contoured shape and aggressive texture improve handling and control without adding unnecessary bulk. Compatible with 10, 20, 30, and 40-round magazines. Features Made in the USA ; 3 Dos Boots Included; +2 Magazine Capacity; Tool-less, drop-in replacement; Impact resistant injection-molded polymer; Aggressive tread; Convex shape; Improved grip surface; Compatible with Magpul PMAG 10/20/30/40 GEN M3 Magazines;