3.5 in. black body of thermoplastic. 3-LEDs for 100000 hours each 1-green and 2-white that are visible for more than a mile with a 360-degree rotating light. Takes 3-AAA batteries that are included for up to 40 hours. 2.4 ounces. Twist for constant on/off.ATTRIBUTES Bulb: LED Green Burn Time: 40 Hours Carry System: Clip Lanyard & Headstrap Finish: Black Material: Thermoplastic Overall Length (inches): 3.50 Power Source: AAA x 3 Special Features: Rotates 360 Degrees Submersible: No Switch: Rotary Switch