Great for training and practice, this 22 LR conversion kit allows for inexpensive target shooting with your favorite centerfire rifle. Shoots and functions like the regular AR-15, except the bolt doesn't remain locked open after the last shot, with no significant change in weight and balance. Assembly is incredibly simple and only requires replacement of the original bolt carrier assembly with the Ciener version. No permanent modifications are required for use. Includes one 10-Round magazine, and is compatible with Black Dog Machine 10-, 15-, and 25-Round magazines. For Semi-auto AR-15's only, will not work in M-16's. This kit does not contain an anti-bounce weight or auto trip which are used in fully automatic M16's. NOTE: This conversion is for use with traditional, Right Hand ejection AR-15's only, and is not compatible with any "Left Hand" AR-15 variants.