Visol VAC713 Modern Circular Digital Hygrometer Digital Hygrometer with Precise Readout; Color Coded Humidity Marker (Green showing Ideal Humidity) Shows Digital Temperature; Battery Included (G13A Micro Cell 1.5 V Alkaline Button Cell); Three Black Button on the Back for Calibration (C = Reset, + = Max/Min, - = C and F) 2.55 inches (Diameter) x 0.55 inches (Thickness); Approx. Weight: 0.1 pounds; Included Magnetic Plate with Adhesive; Can be Easily Attached to Any Cigar Humidor; Made with Plastic Comes Packaged in Cardboard Box