Save your GMC tailgate from costly damage with the CURT tailgate sensor. The GMC Sierra MultiPro ™ tailgate and Chevrolet Silverado Multi-Flex ™ tailgate is an innovative new step in tailgate technology, providing a variety of benefits for pickup truck owners. When towing with your GMC Sierra or Chevy Silverado, it is important to protect your tailgate. A ball mount or other hitch accessory inserted in the receiver can become an obstruction for the inner tailgate operation. This hitch cap sensor is a tailgate saver, working in sync with the truck’s electronics to prevent the tailgate from folding down and being damaged by the hitch accessory.