Mobile Plan Center is a self-contained mobile storage system made of heavy-gauge steel. Width adjusts to accommodate up to 18 hanging clamps (sold separately) that measure from 24" to 42". Simply drop in the hanging clamps and lift out as needed. Plan center rolls easily on four 2" ball-bearing, swivel casters (two locking).Mobile Plan Center is a self-contained mobile storage system made of heavy-gauge steel. Width adjusts to accommodate up to 18 hanging clamps (sold separately) that measure from 24" to 42". Simply drop in the hanging clamps and lift out as needed. Plan center rolls easily on four 2" ball-bearing, swivel casters (two locking).