The Mighty Lift is the easiest and most powerful solution for supporting today's heavier, super sized bedding. This best selling design is the ultimate support system for peace of mind. The Mighty Lift QK series uses 2 Cross Supports with 3 Legs on each Cross Support. The Mighty Lift system is for use on angle steel or wood side rails. Pre-drilled holes on the ends of the Cross Supports facilitate ease of installation and rigidity. The Mighty Lift Center Support System fits Queen, King, and California King size beds. The C-clamp adjustment system allows for infinite width adjustment of the Cross Supports.