Promate LED Light Stick Dive Light Product size: 15mm dia x 120mm (L) Soft light glow LED x 1pc (Total length is 4.5", battery compartment is 1.5", and the lighted tube is 3") LED life time: 100,000 hours Battery: LR44 (or the equivalent to) x 3 pcs; Burn time: 50hours; Underwater: 300feet Anti-rust treatment