Gotoh's regular-sized 510 model is the standard for modern acoustic and electric guitars. It is available in either 18:1 SGL510 or 21:1 SGL510Z bodies.
This is a set of six SGL510Z sealed-gear tuning machines in cosmo black finish with modern mini (aluminum) A07 buttons and thumbscrews locking string posts. Gear ratio: 21:1. Attaching screw tab orientation offset at a 45 degree angle. Package includes nuts + washers + wood screws.