(4) Ukulele machine heads (tuners), in a 2+2 configuration.  Chrome finish with black round buttons. Sealed back.  Good upgrade option. 

Requires 25/64" (10mm) headpiece holes

String post is 0.916" long (23mm), with the string hole located 13/16" (20.5mm) from back of each tuner.

Brands Aftermarket

Part # PS02-C