Hello Guys, I was hoping I could get some help. I need to install some new antennas on a non-penatrating roof sled. These need to be covered by a fiberglass canister that has a diameter of 18". I was just going to order a sled and order some fiberglass tubing and retrofit some brackets to hold the canisters in place. After talking to some of my more experienced guys I am told that there are companies that sell these in kits? Can anybody refer me to a company that does this? Thank you for your help in advance.