Sperzel Trim-Lok tuners are ultra high quality "locking" tuners far better suited at keeping your guitar in tune when using multiple tunings or heavy tremolo usage than other locking tuners. Since there is no winding the strings on a Sperzel Trim-Lok tuner, tuning is greatly stabilized.

The Trim-Lok tuners are way too easy to use...

Simply unscrew the locking knob a turn or two until the inner post drops down opening the hole, thread the string thru and pull tight, turn the locking knob tight, the string is now locked. Now tune 'er up which should take approximately a half a turn or so. Once in tune, repeat the process with the remaining strings. Same goes for locking bass tuners. REMEMBER, there is NO TYING or WINDING of the string on the Sperzel Trim-Lok, which stabilizes tuning. There is less stretching of the string because you have taken the slack out by pulling tightly when starting. Also, the string does not have to reseat itself. All very important factors when you do the tremolo gig! You can trust sperzel, they are into tremolo systems big time.