The ETC 22LR receiver is CNC milled to tolerances of .0005”. The material is 6061 aluminum is manufactured with the highest level of craftsmanship. The ETC 22 features includes a rear cleaning port for easy access and simple cleaning. It has an integrated Extended Picatinny rail for all of your optics. Compatible with Ruger 10/22 and most accessories. All burrs and rough surfaces are eliminated for easy assembly and smooth, reliable cycling.