BHR HandRollers are 12 cm (4.75 inches) long and 2.5 cm (1.0 inch) in diameter. You simply roll them with your hand across the clay or up the wall of a pot to create a beautiful pattern in the clay.  The MKM Roller Board can help create long smooth rolls and avoid knuckle bumps. MKM tools are easily cleaned with water and a soft toothbrush.