Spikes Tactical 5.56 Extractor Upgrade kit. Specifications for Spikes Tactical 5.56 Extractor Kit: Manufacturer: Spikes Tactical Fabric/Material: Chrome silicon heat treated and stress relieved shot peened Gun Model: AR-15 Country of Origin: USA Features of Spikes Tactical 5.56 Extractor Kit: Extractor Spring (chrome silicon heat treated & stress relieved shot peened) Viton O-Ring Black Extractor Insert Package Contents: Spikes Tactical 5.56 Extractor Kit What firearm models does the manufacturer say Spikes Tactical 5.56 Extractor Kit is compatible with? The manufacturer suggests that Spikes Tactical 5.56 Extractor Kit is compatible with AR-15Spikes Tactical ST5E600: 5.56 Extractor Upgrade kit