Take accurate measurements at any crime scene without stepping over valuable evidence. These units are ideal for use at the crime scene and as an accessories for the Compass Rose (provided above), allowing for one-person measurements. Each includes a case with belt loop. #5185 is powered by 2 AA batteries and features a backlit display. #5186 is powered by a rechargeable Li-Ion battery with charging unit and features a backlit display and tilt sensor. #5187 features the maximum distance measurment and is powered by 4 AAA batteries. Each measures in feet and meters.