Turnbuckles are needed for some installations of rack safety netting. Horizontal runs from 30 to 70 ft. require (2) turnbuckles, used at the start of the top and bottom cable runs. Horizontal runs over 70 and up to 200 ft. require (4) turnbuckles, used at the start and finish of the top and bottom cable runs. They are not needed for horizontal cable runs under 30 ft. or vertical cable runs of any height, nor are extra turnbuckles needed for extension-style mounting, as they are already included in extension mount kits.