Rubber O rings for sealing gaps between two surfaces. Use to create air and watertight seal between materials or objects. Multiple applications from plumbing to watch repair. Includes assorted sizes 3 to 22mm. Handy storage case with compartments. Rubber O rings for sealing gaps between two surfaces. Use to create air and watertight seal between materials or objects. Multiple applications from plumbing to watch repair. Includes assorted sizes 3 to 22mm. Handy storage case with compartments.