Caldwell Pic Rail Brass Catcher with Heat Resistant Mesh for Convenient Picatinny Weapon Mountable Brass Collection SPECS: Holds 100 rounds of .223 brass EASE OF USE: Zipper at the bottom of the mesh bag makes emptying simple and the brass catcher quickly separates from the Pic Rail for easy cleaning and inspection DURABLE: Heat resistant mesh will not melt during use and the internal wire frame maintains the bags shape even when it is full of brass CONVENIENT: Put an extra Pic Rail mount on other guns and make switching between rifles quick and easy FUNCTION: Mounts to any extendable magazine rifle with a flat top or Picatinny rail hand guard and is compatible with most AR-10/LR-308 models