The DT40M from Extech measures distances up to 40 m. It can calculate area and volume, and the integrated Pythagorean theorem allows the user to perform indirect measurements. Additional features include continuous measurement with Min/Max distance tracking, a 20-point memory, addition and subtraction of sequential measurements, front or back edge reference, and a stakeout function. The large LCD display has a fourfold backlight and a double-molded housing. It also includes a handy built-in bubble level and comes with a wrist strap and batteries.