Made of high quality material safe an eco?friendly non?toxic stable and easy to use necessary watch accessory. Wonderful replacement for the old or broken one easy to install suitable for professional watch repair shop. Light weight and in small size equipped with a box for easy storage convenient to carry when going out. It is one of the professional watch repair tools suitable for watch repairers and amateurs practical for use. Multiple sizes of O?ring are available for use meet your different needs convenient for use.