For centuries yoga has been practiced on grass, hard dirt, or tiger skins; it wasn't until recently that yogis began to use specific mats. Today they prevent slipping in yoga studios. Mats also provide much deserved comfort during Shavasana (laying flat on your back) at the end of your Hatha practice.
Measurements: 4.25 X 1.25 X 1.25 (HxLxW)