Purchased model (Tier 3 Extreme Duty Dual Brush Strip). 8 days in MN. on sand and gravel roads towing a 519. Installed per manufactures specs 3-4” off grade with a realistic load. Product preformed as advertised and the overall quality is top notch. No noticeable rock chips after detailing and only a couple of pebbles on the back deck. Looking to protect your rig from gravel or road hazards highly recommend. Also purchased the wall bracket for storage.