A Diz is used when preparing fiber to spin. Drafting the fiber through the hole helps line up the individual hairs, producing a finer thread when spun.
Though the round Diz is most often seen, the stick diz with mutliple holes works on the same principle.
Round Diz average 1 7/8 inches, though there is one Mesquite Diz that is 1 5/8 inches.
Stick Diz is 2 1/2 inches long and 3/4 inches wide.