Review on 🌞 BougeRV 8 Units Solar Panel Mounting Bracket Set - Optimized for RV, Roof, Boat, Off Grid - Z-Bracket Style for Secure Solar Panel Installation (2 Sets of 8 Units) by Tim Wilson

The screws are designed so you can drill your own pilot hole. Unfortunately, the hole to be drilled is larger than the screw itself (i.e. larger thread diameter). As a result, the screw spins uselessly in the hole it drilled. I had to buy proper screws to make the brackets useful. Also, there are only two screw holes in each bracket. Two screws are not needed on RVs as they typically fit a 1/4" or thinner Luan roof. I drilled a third hole in each bracket. A 3/8" roof opening and 3/4" screws are sufficient and reduce the risk of entanglement in the wiring installed in the roof.