Wittner Finetune Violin Peg, 4/4 sz 7.8mm Made in Germany by Wittner, Finetune Violin Peg, 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.  The finetune peg needs not/must not be loosened or tightened in order to tune the instrument.  It is sufficient to simply turn the head of the finetune peg in the desired direction.  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.  Diameter at the ring is 7.8mm.  Also available larger  see item # 775