Aero Precision SOLUS Bolt Head Parts Kit Black. Specifications for Aero Precision SOLUS Bolt Head Parts Kit: Manufacturer: Aero Precision Color: Black Action Type: Bolt Action Caliber: 8.6mm Blackout 6mm Creedmoor .243 Winchester 6.5mm Creedmoor .308 Winchester Package Contents: Aero Precision SOLUS Bolt Head Parts Kit Standard Extractor Extractor Detent (2x) Extractor Spring (2x) Ejector (2x) Ejector Spring (4x) Ejector Retaining Pin (2x) Bolt Head Pin (2x) O-ring Aero Precision APRH103339C: SOLUS Bolt Head Parts Kit Black