Carlson's Auto Catcher for 12 & 20 Gauge shotguns is a durable steel device designed to catch empty shells and prevent them from being ejected through the receiver on semi-automatic shotguns. It holds the spent shells for easy collection and helps keep your shooting area tidy. This model is compatible with most 12 and 20-gauge semi-auto shotguns. To install, just peel the backing off the included double-faced tape and attach the catcher to the receiver. The semi-permanent adhesive can be removed if necessary. The padded tape prevents the metal plate from touching the gun, eliminating any risk of scratching the finish. The Auto Catcher can be adjusted to accommodate different shot shell sizes and firearms by simply adjusting the wire ends, without any need for modifications to the gun itself.