3/4" x 4" in diameter, a Zebra Round Wooden Rib for Throwing Perfect Bowls by Hsin-Chuen Lin.
Care and maintenance:
They should not be left in the water or shurry bucket for a long time. After finishing, use a sponge to clean the surface, and set out to dry. In a couple weeks, apply mineral oil on the surface and you can continue to enjoy their beauty and function!