This is the A5 Barrel Adapter for the CCM SR1, SSR, and SSPAR first strike rifles.  The adapter allows for the use of A5 threaded barrels on a CCM first strike rifle and features external threading for mounting handguard delta rings.

   CCM products are designed and manufactured in the United States and are machined from high quality materials such as 6061 air craft grade aluminum, 300 series stainless steel, and durable plastics such as delrin and lexan.
MADE IN THE USA