Bolt's glute-ham developer is a multi-functional machine that works out your calves, hamstrings, glutes, and lower back. This machine is not only compact but also extremely stable. Made with 11 gauge steel, and welded together, we believe all equipment should be built to last. Uniquely, we've included 2 sets of handles which will help the athlete stabilize themselves throughout their different workouts. For full adaptability, there are 12 one-inch adjustments, so athletes of all sizes can enjoy the GHD.