This is the Princeton Tec League 420 Handheld Backup Scuba Diving Light Features: Princeton Tec&';s brand new handheld waterproof dive light Light weight and comfortable shape The ideal backup light in the water This unobtrusive light hides out of the way until it is turned on The sculpted shape makes it feel like an extension of your hand Provides impressive output for its size Up to 10 Hours of Burn Time A Powerful 420 Lumens 1 Maxbright LED Lamp Powered by 4 AA alkaline batteries Weighs 203 grams Designed for power, comfort and durability, this back-up light packs a powerful punch and is certain to outperform your expectations.