Gibraltar SC-GRSRAA Road Series Ratchet Assembly Clamp Rack Clamp with Arm Assembly The SC-GRSRAA RS (Road Series) Rack Clamp with Ratchet Arm Assembly is a rack bar clamp with L-Rod ratchet assembly The SC-GRSRAA RS (Road Series) Rack Clamp with Ratchet Arm Assembly is a rack bar clamp with L-Rod ratchet assembly