Product Description：This coupler is designed for rifle Magazines in .223 and 5.56 x 45mm. It will work on Magpul, ProMag and Most other brands.This Coupler allows the user to attach two magazines together for more efficient speed reloads, and to keep additional ammunition accessible on the weapon at all times. This Coupler features a two-piece Spring Loaded 2 Bolt design and is very durable and lightweight.Reinforced Black Polymer Construction, which resists operational abuse. Wide-set, two-piece design resists flexing and integral grooves interface with ribbing to eliminate slippage during transport or use.Package Include:1 x Nylon magazine parallel connector