Joseph Pilates invented several pieces of equipment, each with its own series of exercises.   The most common apparatus is the Reformer, but other equipment includes the Cadillac (also called the Trapeze Table), the Wunda Chair, and the Ladder Barrel.
Lesser used apparatus includes the Spine Corrector (Step Barrel), the Guillotine Tower, the Arm Chair, the Ped-a-Pul (Pedi-Pole), and the Foot Corrector.

The reformer, wunda chair, cadillac and barrels allow the placement of the body in a non-weight bearing position.  This allows participants to strengthen and stretch their bodies without any stress or pressure on the joints.  It is the spring tension that works in a similar way to muscle contraction that allows this to work.  With the assistance of the spring contraction, the body is taught to move correctly and efficiently.