Leica DISTO E7100i 200ft Laser Distance Measure with Bluetooth, Black/Red This unit contains a Class II Laser with 1mW output 1/16" ACCURACY up to 200-FEET MEASURING RANGE. That's right, a sixteenth of an inch. Take out a pair of earbuds. Look at how wide the 1/8" jack is. Now divide that by half. BLUETOOTH 4.0 for transferring measurements into desired software. Send measurements directly from the laser measure to your apps using the Leica DISTO Bluetooth Smart (4.0) wireless data transfer. IP54 CERTIFIED - DUST & SPLASH PROTECTED. Per set of AAA Batteries, capture up to 5,000 measurements. MIN/MAX FUNCTION. In Min/Max mode, you "sweep" the laser point into a corner. The longest measurement is recorded. Very useful for accurate diagonal room or window/door measurements. AREA/VOLUME FUNCTION. In Area Mode, this laser distance measure determines the area of a rectangle or square in two shots. Volume Mode adds a third vertical shot to calculate volume.