Adjective
boltless (not comparable)
Without bolts (mechanical fasteners).
Square-hole racks allow boltless mounting, such that the rack-mount equipment only needs to insert through and hook down into the lip of the square hole. Source: Internet
Installation and removal of hardware in a square hole rack is very easy and boltless, where the weight of the equipment and small retention clips are all that is necessary to hold the equipment in place. Source: Internet