The Brass Buster is designed as a removable and ambidextrous polymer brass deflector to allow weak side shooting with the Steyr AUG and Steyr AUG clones. Simply press the Brass Buster down onto the stock behind the ejection port with the projection on the ejection port side. Regardless of if your ejection port is on the left or right side of the gun the Brass Buster can be installed.