Check the listing for details. Grover 102CV Original "Milk Bottle" Style Rotomatics Tuning Machines Set -. Condition: New. Listed at 84.99 USD. Grover Rotomatic 102CV guitar tuning machine heads are a marvel of engineering and design. Rotomatics have a gear ratio of 18:1, and a housing that provides optimal bearing for worm, gear and string post. Precision-cut worm and gear serve up perfect meshing, eliminating backlash and slippage. A countersunk tension screw lets you customize tension to your personal preference. The Rotomatic's gear box is permanently lubricated, giving you a lifetime of trouble-free operation. Sweetwater knows that keeping your guitar in tune is important, and we're confident that Grover tuners can do the job. Washers, bushings and wood screws are included with this set of six Grover Rotomatic 102CV vintage-styled guitar tuning machine heads.