Cabling should be attached using hook clips or other wiring retainers that do not crush conductors. If there are many cables in a path, hangers should be affixed to support the bundle. Cable ties can be applied but should not be over-tightened. Excess tightening can pinch the wiring, whereas a loose tie will allow cables to slide easily back and forth within the bundle. Using hook-and-loop straps during the installation can ease cable pulling since the straps can be nailed to studs or joists. Cables can then be pulled through the loose opening with little force. To reduce the risk of damaging or tangling the cables, pulls should be made in stages when the paths are long or have many turns. Never exceed a stretching or pulling tension of 25 lbs since this may cause the wire pairs to untwist.