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 desired. The receiver is machined to utilize their threaded receiver pins. The KIDD upgraded bolt buffer will cushion the felt recoil of the bolt. The optional rear tang will increase your stability of the rifle but require some custom inletting to your stock. (See rear tang installation instruction below) We also have the additional option of a second scope base due to the interchangeable nature of this base you may want to purchase two. So, for instance, if you were going to change from shooting 25 yards to 150 yards and your scope needed some help with that adjustment, you could switch out the base. Both the scope base and rear tangs have mating designs to the receiver so that the rifles have great rigidity as well as some customization aspects. 10/22 style aftermarket slip fit receiver Durable anodized finish Billet aluminum Rear access cleaning hole Optional v-block, rear tang, take down screw, bolt buffer, and pins Specialized interchangeable scope base Receiver comes standard with Zero scope base installed