JE Machine Tech A2 .308 Buffer Spring Long Black. 308 Buffer Spring: Manufacturer: JE Machine Tech Color: Matte Fabric/Material: Steel Gun Model: AR-10 Condition: New Additional Features: Constructed from piano steel Caliber: .308 Winchester Features of JE Machine Tech A2 .308 Buffer Spring: Full length recoil spring Precision centerless ground Provides excellent impulse feel resulting in faster sight recovery and improved reliability Constructed from piano steel Package Contents: J&E Machine Tech A2 .308 Buffer Spring What firearm models does the manufacturer say JE Machine Tech A2 .308 Buffer Spring is compatible with? The manufacturer suggests that JE Machine Tech A2 .308 Buffer Spring is compatible with AR-10JE Machine Tech PS-ABT3: A2 .308 Buffer Spring Long Black