IKN White Ukulele Tuning Pegs Pin Machines Tuners Pack of 4 Set of 4 pcs Strings Tuning Pegs for Ukulele part replacement. The central peg is made of steel.A small screw at the top is used to adjust the pressure. The end of the shaft about 6 mm in diameter. Material:Metal with plastic.Color:silver with white button. Package Including:4 x Ukulele machine heads.