Locking vintage-style Gotoh SD91 set of six tuners, ideal for a vintage Fender Stratocaster or Telecaster. 15:1 gear ratio. The locking mechanism works by inserting the string through the hole in the post as per usual but making sure that you hold the end of the string taught while turning the tuning machine button and this will automatically clamp the string into place. Once the string is locked, simply continue to tune to pitch and you won't need to wrap the string around the post more than once. The advantage of such a discreet locking mechanism, without the usual large locking wheel at the back of the tuner, is that it retains the vintage look of your headstock but with the added advantage of having the solid stability of a locking tuner. When it comes to string changing, simply detune the old string and use a flat head screw driver or a coin in the slot at the top of the post to undo the locking post which will in turn release the string. Sold as a complete set of six and comes complete with push-fit bushes and mounting screws. The diameter of the push-fit bushes is 8.8mm - ideal for any 6 in line headstocks that already use vintage-style push-fit bushes. If your headstock is drilled out to 10mm then you will need to also order a set of the Gotoh adapter bushes. Please refer to the secondary image for detailed measurements of the tuners and push-fit bushes to insure that they will fit your guitar.