Anti-rust treatment, Product size: 15mm dia x 120mm (L)
Super bright 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
This is no intention to replace flashlight, but a soft light glow, diver recognition, marker lights perhaps.