Cobalt Kinetics Stripped Upper Receiver Group 6.75in Black. All CK-Pro URGs are expertly built by gunsmith staff. Built URGs are test-fired for function before leaving out the door to the customer. Specifications for Cobalt Kinetics 6.75in Stripped Upper Receiver Group: Manufacturer: Cobalt Kinetics Color: Black Finish: Cerakote Package Contents: Cobalt Kinetics 6.75in Stripped Upper Receiver Group Cobalt Kinetics STRIPPD URG 6.75 BLK CK-PRO-URG-675-S-BLK