The 406 Series gives you the same innovative engineering and classic design as the Standard Locking Rotomatics, but with smaller buttons for 6-in-line guitars, or for those who prefer a little more space for their fingers. Simply insert the string through the string hole, pull to tension by hand and begin tuning. As you start to tune, only the locking cam in the string post turns. Once the string is locked, the string post begins to turn allowing you to bring the string to pitch. In less then one revolution of the string post, you will be in tune, and stay in tune. Gear ratio is 18:1.