When it comes to hygrometers, accuracy is everything. That's why your choice should be reliable above all else. Zederkoff Hygrometers can be counted on to deliver precise results time after time, and boasts the industry leading accuracy of +/- 2% RH, with no adjustment needed. It comes with an adhesive magnet that easily attaches to your humidor. Get the best and forget the rest, and keep all of your prized cigars in peak condition with this highly dependable hygrometer.