Cobalt Kinetics 13in CK-PRO Aluminum Stripped Upper Receiver Group Black Cerakote. All CK-Pro URGs are expertly built by our gunsmith staff. Built URGs are test-fired for function before leaving out the door to the customer. Upgrade your current platform RUN COBALT Specifications for Cobalt Kinetics 13in CK-PRO Aluminum Stripped Upper Receiver Group: Manufacturer: Cobalt Kinetics Finish: Cerakote Fabric/Material: Aluminum Package Contents: Cobalt Kinetics 13in CK-PRO Aluminum Stripped Upper Receiver Group Cobalt Kinetics CK-Pro Urg Aluminum Black Cerakote Receiver CKPROURG13SBLK