Nightstick TAC-400 Series Rechargeable Tactical LED Flashlight Light Source: LED Power Source: Rechargeable Lithium-ion Back-up Power Source: 2 - CR123 Lithium Batteries (not included) Case Material: Glass-filled Nylon Polymer Type of Switch: Single Tail Cap Switch - Momentary or Constant-on Flashlight Length: 6.25 in (159 mm) Handle Diameter: 1.035 in (26 mm) Head Diameter: 1.25 in (32 mm) Weight: 4.9 oz. (140 g)