The Hi-Lift Jack Versatile Locking Knob is a must have for any Hi-Lift jack owner. The Versatile Locking Knob replaces an existing knob or the wing nut provided on standard Hi-Lift jack mounting kits. Once tightened, the Versatile Locking Knob can be locked with the provided key. The Versatile Locking Knob works with Hi-Lift model numbers: 4X400 4XRAC Mounting Rack, Adjustable Tube Mounts - TM-700 and TM-750 and the LR-200 Loc-Rac. It can also be used to secure the Winch/Clamp/Spreader attachment on Hi-Lift XT-485 and XT-605 X-treme jacks as well as UTV-364 and UTV-424 UTV jacks.