Strike's AR-10 308 Ultimate Dust Cover is constructed of a high-density polymer making it more durable and functional than the traditional dust covers. It features an adjustable detent set screw in order to compensate wear on the receiver and increase or decrease opening power. This model features a capsule design.It is constructed of a high-density polymer making it more durable and functional than the traditional dust covers. The Ultimate Dust Cover features an adjustable detent set screw in order to compensate wear on the receiver and increase or decrease opening power (To adjust detent: use small flathead driver and depress the ball detent and adjust as necessary). Features: Patent pending spring-loaded, internal detent rod for easy installation and take-down Constructed with lightweight durable polymer material Will never corrode rust or fade Will never deform or get bent out of shape Comes in a variety of designs Patent pending, true seal internal lip that seals the port tighter than traditional dust cover designs Built-in adjustable detent set screw to compensate for wear on the receiver