The Plumber's Choice 1-1/2 in. Steel Cable Clamp; Hangs Tubing, Wiring, Ropes, for PEX, Plumbing, Marine, Automobile; Galvanized 112CPSWG - The Home Depot
National Hardware 1/2 in. Wire Cable Clamp, Zinc Plated at Tractor Supply Co.
Wideskall 8 Pcs 1/2" inch Adhesive Black Nylon Adjustable Cable Clips Wire Clip Black - Walmart.com