RYLA Black Alloy Case Men Wristwatch 2015 Sports Military Quartz Japan Movement Clock Watch Weight: 0.08 kg Dial is 4.8 cm in diameter Band material: high quality silica gel Level is waterproof, life waterproof (belong to light waterproof do not wear bathing, swimming, etc.) Note: the first on the right key is adornment, to adjust the time Need to unscrew the second key.