The Alexander Arms Magazine for the 17 HMR is a tough polymer magazine with a durable body. The magazine body features unique indentions which allow you to easily swap between magazines at the range. Moreover, the magazine feed lips are smooth for added protection. Each magazine is precision machined to produces perfect consistency and is designed to last for years to come. FeaturesTough Polymer ConstructionSmooth Feed LipsEnvironmentally ResistantPrecision Machined Note: Compatible with the Alexander Arms 17 HMR AR-15 only