Nickel plated, 3-left/3-right. These tuners are used on Duesenberg Doublecat 12-string and Mandola 12-string guitars. They feature knurled knobs instead of tuner buttons. This allows an installation with less distance between the tuners. Two pin mount keeps tuner from rotating, no mounting screws required. For a 12 String headstock you have to order 2 sets. The strings are just put all through the tuner (see details for more info). For 10mm pegholes, 15:1 ratio. Threaded hex bushings included.
The end of the string is - like used to - cut but on the backside of the headstock. Then press it back 1mm by the tip of your thumb to avoid dangerous sharp ends. After that turn the button until the string is in tune.