Transformer 2" Tubular X base series offers two separate height ranges: approximately 8" and approximately 11-7/8". The shorter one covers the sit-down work height range including ADA requirements. The taller one includes sit-down to stand-up work heights. Adjustment is easy. Simply set your foot on the base and lift the surface. The mechanism will automatically adjust to the next level. To lower the surface, lift it to its highest level. It will release and slowly descend to the lowest position. No locks, no levers, no cranks, no cylinders, no pins, etc. Gibraltar’s Transformer Series offers one of the most user friendly, multipurpose, and cost-effective lines of adjustable height bases and mechanisms available today.