DC Gaussmeter GM1-HS with Aluminium Carrying Case High dynamic range/sensitivity:reads up to 799.99 gauss with .01 gauss resolution incl. polarity. Instant on, updates four times a second, with no setup or initial calibration required. Size:5.2 x 3.6 x 1.6 inches; 132 x 91 x 41 mm Flexible probe and battery are included; Offset range is the full +/- 799.99 gauss. Auto-Zero (subtracts the present field from subsequent readings); also a fine offset control.