The SRWC is a special design quick release weaver rail clamp specifically designed for RC220 and RC500. It can also be bolted on to Light Force RC225 and MagForce.
It's original design purpose was to convert the PowaBeam Light Bracket to a quick Release option which can be bought with the rail in a complete kit.
The package includes:
1 x Weaver Rail Clamp (SRWC)
1 x Fastener Kit