T-Bell®Versatile and indestructible, the T Bells patented biomechanical design engages the correct muscles while promoting proper form and reducing stress on the spine. By keeping the weight closer to the center of gravity and aligned with the spine and hips, the T Bell strengthens the posterior muscle chain including biceps, femoris, gluteus maximus, erector spinae muscle group, trapezius, and posterior deltoids the core power muscles that boost performance