Leveling glide mechanism, inside side panels are slotted for shelves and accessories, shelves can be added as will, knock down structure. Note: Swing door cabinet, sliding door cabinet, glazed door cabinet, roller shutter door cabinet can be combined as will. Model and size: SE-OP20--W900*D450*H2047(mm) with 4 adjustable shelves. SE-OP18--W900*D450*H1820(mm) with 3 adjustable shelves. SE-OP13--W900*D450*H1377(mm) with 2 adjustable shelves. SE-OP10--W900*D450*H1050(mm) with 2 adjustable shelves. SE-OP07--W900*D450*H 722(mm) with 1 adjustable shelves. Option accessories: Pull-out desk top, pull-out frame, pull-out drawer, hanging rod, cloth hanging rod, divider, pigeon hole. Color: Beige, gray and black for body, black and gray for shelves.