Laser Genetics ND3 Subzero Laser Designator Functions well in temperatures 40-deg. F or colder Green laser with Rotary Optical Collimator* Adjustable beam diameter & intensity Micro-beam is visible up to 3 miles Wider beam illuminates trails or "paints"targets up to 250 yds away Water-resistant Nitrogen-filled to prevent fogging (o-ring sealed) 532nm laser 18mW output Class 2M Uses 1 CR123V lithium battery 1"tube 6.75"long 1.25"dia. lens 5.37 oz. Fully multi-coated lenses Made of high-tech aluminum Anodized matte black finish Includes one CR123A lithium battery, Weaver ring, binocular/spotting scope mount (9.2mm to 6mm long, 1.25mm threads), scope mount, remote momentary pressure switch, cleaning kit, hex wrench, lens cap & padded case *The patented Rotary Optical Collimator uses a system of 9 fully multi-coated lenses that allow full adjustment and control of the beam diameter and intensity to focus light where it's needed most. Rotating the collimator ring to minimum creates a bright micro-beam green laser light visible up to 3 miles. Rotating the collimator to more open settings provides plenty of illumination to light a trail at night or ôpaint"a target up to 250 yds. away. Do not stare directly into the laser beam or view directly with optical instruments. Viewing the laser light or a bright reflection may cause eye injury.