40" on a 120gal. 48"x24" base. The cabinet was made with oak veneer finish 3/4" marine plywood. If its well made and reinforced it will hold up an elephant. I love the stand in front and its right in your face deal too! Plus it offers room beneath to have a gravity fed double stack sump set up. Yea I use a step stool mostly during water changes, other than that, my hands seldom need to go into the tank. I have about 5 1/2' ft of head pressure to work against and the circulation is great. You have to choose the right pump considering head pressure. Another common mistake is reducing the size of the plumbing. If the pump has a 1" outlet then keep plumbing at 1" until it reaches its highest point. Some tanks come with 3/4" bulkhead fittings at the bottom inlet, if this is the case then reduce the diameter right under the bulkhead fitting.