Wittner, Rosewood Color Finetune CELLO 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 cannot 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 peg hole (the shaft of the peg does not spin, subsequently there is no friction). Climate and humidity have no influence on the peg. These pegs should be installed by a professional luthier or repair person only. See specification tab below to determine size.