This AR-Style Magazine Dust Cover improves the quality of your shooting experience by reducing malfunctions caused by ammo jamming or feed lip damage. Simply slip the magazine dust cover over the top opening of the magazine to block dust, dirt and other debris from getting into the magazine causing loading issues. May also prevent the transfer of debris from the mag to the chamber to support proper seating of the rounds. The cover is made from a durable rubber compound that is impervious to ozone deterioration, water, acids, bases, grease, sales, oil and alcohol. It can also withstand temperatures ranging from -20° F to 250° F. Fits metal and polymer AR-style magazines in all sizes and calibers. Made in the USA by Cammenga.