Chirp Wheel+ 3-Pack.Say goodbye to back pain with the Chirp Wheel+ 3 Pack. This bundle features three different sized wheels for optimal back pain relief and muscle recovery. The 12 Gentle delivers a wonderful stretch and light massage, the 10 Firm adds a little more pressure to help you massage those problem areas along the spine, and the 6 Deep Tissue digs in deep to get rid of your toughest knots.