JP Enterprises Enhanced Carbine Buffer Tube Hardcoat Anodized Black. The manufacturer have included an addition stock position (for a total of seven) and given a finer surface finish for smoother function. This design is also designed to allow extra threading into the receiver which optimizes protrusion for use with JP Silent Captured Springs. Specifications for JP Enterprises Enhanced Carbine Buffer Tube: Manufacturer: JP Enterprises Color: Black Finish: Hardcoat Anodized Fabric/Material: 7075-T6 Aluminum Gun Make: AR Platform Gun Model: Universal Gun Type: Rifle Length: 7.25 in Condition: New Features of JP Enterprises Enhanced Carbine Buffer Tube Addition stock position stop compared to standard Mil-spec 6-position design Extra fine internal finishing for smoother quieter cycling and reduced buffer component wear High quality exterior finish for reduced buttstock friction Allowance for further insertion into lower receiver to optimize protrusion for use with Silent Captured Springs Fully Mil-spec compatible Package Contents: JP Enterprises Enhanced Carbine Buffer Tube Lock Plate Lock Ring What firearm models does the manufacturer say JP Enterprises Enhanced Carbine Buffer Tube is compatible with? The manufacturer says that JP Enterprises Enhanced Carbine Buffer Tube is compatible with UniversalJP Enterprises JPBT-CA: Enhanced Carbine Buffer Tube Hardcoat Anodized Black