Tired of throwing away chemical light sticks after every use? Tektite&';s Mark-Lite is The Original battery operated submersible marker light. Use one in the dark in place of a chemical lightstick while scuba diving, camping, jogging or biking. Every Mark-Lite features a reliable, twist-on switch and uses 1 AA battery. Lasts hours-with an operating cost of less than 20 cents/hr. Save money while helping keep our environment and oceans clean. Available in your choice of four popular lens colors. A bungee lanyard is included. Free 1 AA Alkaline Batteries Included! Free Lanyard Included! Depth Rating: 1,000 feet (300 m) Bulb: Krypton Bulb Life: 25 hours Burn Time: 3+ hours Batteries: 1 AA Alkaline Materials: ABS and LEXAN Dimensions: 5.75 (15 cm) L x 1.2" (3 cm) Dia. Weight: 0.38 lbs. (0.17 kg)