Blitzkrieg Components Sprinco Power Buffer Spring, AR15 Carbine. Significantly reduces the BDC value while boosting the BDR of any AR-15 platform. These BK Components AR15 Lower Parts made by Blitzkrieg Components utilize a chrome silicon steel material that is incredibly durable and efficient while keeping the springs light and compact. The Sprinco Power Buffer Spring resists buckling and damage and provides the proper B.A. that keeps your round trains on target. Package contents: Blitzkrieg Components Sprinco Power Buffer Spring, AR15 Carbine. Compatible with AR-15 platform rifles.