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. MKM rollers are finished with tung oil to ensure durability over many years of use. MKM tools are easily cleaned with water and a soft toothbrush.