Cable guides and sleeves protect against falls that can occur on ladders. Cable guides are thin, steel cables that run alongside ladders. A cable sleeve attaches to a cable guide and contains a steel wire rope and snap hook that fastens to a worker's harness. If the worker slips off a ladder, the cable sleeve locks in place on the cable guide. Many cable sleeves also absorb the shocks of a fall. They must be replaced after a fall occurs.