Designed for AR-style rifles, our SPR (Special Purpose Rifle) mounts are ultra-durable with minimal weight and bulk. Their specialized, sleek design delivers optimal height with a forward cantilever for AR platform rifles. They are constructed of lightweight, strong, aircraft-grade,6061-T6 aluminum with a durable, black matte anodized finish. Two models are available, designed for 1-inch or 30mm tubes..