Planet Waves Auto-Trim Tuning Machines, 6 In-Line setup, Black 6 High quality precision tuners that automatically cut excess string while the guitar is tuned; 6 In-Line 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 Limited lifetime guarantee