6 High quality precision tuners that automatically cut excess string while the guitar is tuned; 3 + 3 format Individual string clamps securely hold the string in the tuning machine, avoiding the need for multiple wraps around the post Excellent for tremolo use and other demanding applications | Precise 18:1 gearing ratio for smooth, exact tuning with minimal string slippage - diameter of tuning post 0.375" Limited lifetime guarantee |