Features: *The Opener tools Adopting premium steel material with stable construction, it is rustless.And which is high hardness, good toughness, strength and durable. *Package Included: 1 x Wrench 6 x Different Size of Grooved Check(Rings);Size: NO.0--18.5mm,NO.1--20.2mm,NO.2--22.5mm,NO.3--26.5mm,NO.4--28.3mm,NO.5--29.5mm. *Great for opening and closing waterproof and grooved watch back case.Professional Watch Maintenance Tools is useful for watch repair works. *Light and handy design makes the Tool more Easy and handy to take with you because its small size and light weight. Easy to Open the Watch Back Case without Scratching. *The Watch Opener Tool great for watch repairers professional or amateur in the Watch field, you can easily open Watch by using the tool. Specification: Size: NO.0--18.5mm, NO.1--20.2mm, NO.2--22.5mm, NO.3--26.5mm, NO.4--28.3mm, NO.5--29.5mm Packaging includes: 1*Wrench 6*Different Size of Grooved Check(Rings)