The KIDD .22LR Classic Receiver is an aftermarket receiver. It is a slip-fit design with industry standard dimensions. The Classic is designed with the easy access rear cleaning hole and a proprietary interchangeable low scope base with varying minute of angle (MOA) available. Zero MOA is great for 50 yards and under 20 MOA is helpful for 150 yards and over. It is designed to drop into a stock inletted for the 10/22 without any modification. This receiver is milled out from 6061 T6 aluminum and anodized either black or clear. Recommend using a KIDD trigger with a KIDD receiver. KIDD has provided the option to build this receiver with receiver pins, bolt buffer, or rear tang if desire Mfg: Kidd Innovative Design