Dental Probe 23 / UNC15 Explorer Color-Coded Markings at 1-2-3-4-5-6-7-8-11-12-13-14-15. To measure the defect size and the membrane at a GTR therapy The thin, unbreakable, yet flexible tips from a special steel alloy guarantee an extremely long life All our Periodontal probes are prepared by a high-speed cutting machine. Working parts are in very fine to very precise dimensions and the color markings are (do not dissolve or fade off) ultrasound-resistant. non-slip handle lies very well in the hand, allows grab a relaxed and prevents fatigue.