The 1SKB-R1906 was designed to add expandability to the 1SKB-R102, 1SKB-R104, 1SKB-R106 and 1SKB19-R1208 as well as the 1SKB19-R1006(V) and the 1SKB19-R1010(V). The 1SKB-R1906 can even stack on itself (remove the casters from the top one before stacking). There is a 1" border around the top of the case (to help hold whatever is on top, in place). So the actual depth (height) is 16" and if you include the wheels, it's 21" (20" from the bottom of the wheels to the top mounting surface) . **This product is prohibited from shipping to California.**, Lot of 1