Slotted hook-and-loop cable ties have a slot (also known as a loop) in the head that the strap feeds through. The strap may be pulled tighter or looser to control the bundle tension. It folds back on itself to engage the hook-and-loop material for a secure fit. These cable ties come in premade lengths, so they're ideal for wrapping bundles that have a predetermined diameter. They must be overlapped to achieve their tensile strength.