All 18" D x 24"W shelves have a 1/4" safety retaining lip and a raised texture surface.3-outlet UL listed electrical assembly with a 15 ft. cord, cord management wrap, and three cable management clips.Electrical attachment is recessed to insure easy passage through doorways.Four 4" silent roll, full swivel ball, bearing casters, two with locks, max. weight rated at 125 Lbs. each.