Designed specifically for slide presentations, wall charts, and field use. Pointer’s brilliance works equally well in daylight or dark. Output is 4 mW with a range of 400 feet. Beam is at the highly visible 650 nm wavelength with diameter of 3.5mm. Key-chain makes it easy to carry. Supplied lithium battery powers unit for a year of intermittent use. Size is 2-1/2 x 1 x 1/4 inches, and weight is 1/2 ounce.