Wittner internally-geared "Finetune Violin Pegs" put the other planetary geared pegs we all know about (and we used to sell) to shame. Much kinder to the pegbox, as they are held in by friction like a regular peg instead of screwing and gluing...in other words, you DO NOT ruin your pegbox. Much more durable than the competing planetary pegs and the gears don't strip, like the other ones have for us many times. Comes in two diameters, as measured where the red arrows point in the photo, 7.8mm

Made in Germany by Wittner, the Finetune Violin Peg provides very easy, quick, effortless and very precise tuning. Made of high tech composite material and light alloy, the tapered peg is put in place without glue by simply pressing it into the pegbox just like any ordinary peg.  Self-inhibiting transmission inside the peg; the string can not lose tension. Users of other brands know that the pegs often slip a semitone or two after tuning.  Because, once installed, you only turn the button rather than pulling and pushing the peg out and into the pegbox, there is no wear on peg and peghole ( the shaft of the peg does not spin, subsequently there is no friction).  Climate and humidity has no influence on the peg.  4/4 size only.