KAK Industry K-SPEC Enhanced Bolt Carrier Phosphate Black. The K-SPEC is a truly plug and play BCG that will accommodate whatever configuration your mission requires. Specifications for KAK Industry K-SPEC Enhanced Bolt Carrier: Manufacturer: KAK Industry Additional Features: Bolt Carrier Condition: New Features of KAK Industry K-SPEC: Full Auto Profile Package Contents: KAK Industry K-SPEC KAK Industry 204-0412-001: K-SPEC Enhanced Bolt Carrier Phosphate Black