Aqua Vim glass tanks come with built-in three-level intake overflow boxes (larger tank sizes have 2 overflows) and predrilled 1.5 drain and 1 return holes for plumbing, and an additional 1/2 predrilled opening for running wires through the overflow box. Tanks are top-braced with glass rims for maximum structural integrity. The drilled feeder hole in the brace of the tank allows for accessibility and convenient feeding. For ease of setup, dual openings in the back corners of the brace allow for customization and wiring of internal tank accessories such as air pumps, heaters, and wave makers. Aquariums come with a black vinyl background attached. Every tank is paired with wood cabinetry handcrafted by our master carpenters. The double-sided front-open 12 canopy features a wood prop that allows for hands free maintenance and lighting hooks / cooling fan slots for even the most dedicated of lighting enthusiasts. The 34 stand has cabinet doors in the front and back, and is fastened with soft close steel hinges and easy-click magnetic door closures for effortless access. The center beams on either side of the stand are removable, providing ample space for moving around equipment during setup. See Specifications Chart for more detailed product information. NOTE: Due to the handcrafted nature of our aquarium sets, there may be minor variations in the dimensions and bracing style. Cylinder tanks are made with two pieces of half circle glass panels joined together, and have a seam on either side for increased integrity.