Go look at the design of the antenna. (See image below). The unit I have purchased for my past two coaches is about 7 inches in diameter with wires coming straight down from the center of the unit. It has super sticky tape all around (360 degrees around) the wires on the flat surface of the antenna. I clean the roof section of the coach very good with 3M Adhesive remover to get a nice surface for the sticky tape, then feed the wires down through the hole and press like hell to get the tape seated. The antenna has a large nut and washer to give added clamping pressure to the coach rooftop. Tighten that fully. I then take RV roof sealant (buy it at Camper's World) and run a bead around the outside edge for added security. Never had that system leak.