Jewelry Watch Case Screw Back Opener Wrench Large V-Shape Watchmaker Repair Tool This is a Watch Case Opener which opens and closes back of water resistant watches. The professional Watch Back Opener is made to easily open any type watch or brand watches with a non screw watch case. The adjustable jaws of the Watch Cover Opener will safely fit your watches and incorporates a long handle with sturdy construction to eliminate the risk of slipping. Great affordable way to change watch batteries or inspect watch movements by this Watch Repair Tool. Max diameter:36.5mm. Length:144mm. Package size:150*65*35mm