Features 1、Rubber O-Ring watch gasket used to keep your watch water resistant. 2、Made of rubber material, flexible and wear-resistant, durable to use. 3、Including 500pcs of the Package, meeting your different needs. 4、Excellent replacement for the watch back cover seal gaskets. 5、Suitable for watchmakers and watch repairing workers to use. Specification Features: Rubber O-Ring watch gasket used to keep your watch water resistant. Made of rubber material, flexible and wear-resistant, durable to use. Including 500pcs of the Package, meeting your different needs. Excellent replacement for the watch back cover seal gaskets. Suitable for watchmakers and watch repairing workers to use. Specification: Condition: 100% Brand New Material: Rubber Quantity: About 500pcs 0.7: 16mm /17mm /18mm /19mm /20mm /21mm /22mm /23mm /24mm / 25mm /26mm /27mm /28mm /29mm /30mm 0.8: 31mm/ 32mm /33mm /34mm /35mm /36mm /37mm /38mm /39mm / 40mm Package List: 1 x Bag of O-Ring (including about 500pcs)