Class III/IV hitches are Weight Carrying (WC) and also are Weight Distributing (WD) hitches depending on the vehicle and hitch specifications. Not all Class III/IV hitches are rated to be both. The hitch specifications will alert you to a hitch that is not weight distributing. Class III/IV hitches used as Weight Carrying is rated up to 6,000 lbs. Gross Trailer Weight (GTW) with a maximum trailer Tongue Weight (TW) of 600 lbs. The use of a ball mount and hitch ball of the same rating or higher is required. To use the weight distribution side of the hitch a weight distribution system is required. Class III/IV hitches attach to the vehicle frame only. Always consult your owner's manual for vehicle rating. T-One connectors require no splicing of wires. Simply locate your vehicle's wiring harness connector, unplug the connection and insert the T-One Connector into the vehicle's harness. No special tools required. Many units now include circuit protection for your safety. Fits 2008-2012 Buick Enclave and 2009-2012 Traverse.