4pk 4" j-hook. Patented design snaps pipe into place before attaching to joists, rafters, or studs. Made of high-impact ABS. Nail holes on all 4 sides. Nails included. 1/2", 3/4", and 1" will work with copper, CPVC, polybutylene, or PEX tubing. 1-1/2" thru 4" will fit Schedule 30 and Schedule 40 DWV pipe. May also be used for utility use to hang bicycles, hose, tools, etc. Packed in poly bags. 4", 4 per bag