Desgined for use with 22LR AR conversions. 25rd Capacity. 25 Round Skinny 22LR in Black Short Skin Body Fits Any Standard AR15 Magazine well Polymer Skin and Core It is important to note that this magazine does not work with the BHOA, it physically holds the bolt open once the last round has been fired. (We have been told the Magazine also works with the following Atchisson, Ciener, CMMG, Model 1 Sales, Spikes Tactical, Tactical Solutions, Target Master, CMMG Raven.)