R atings and Specifications Model HKT-3020 (main unit) Used power supply AC100 V to 120 V, 50/60 Hz Wattage Approximately 27 W Usage environment Temperature: 41 to 95 ° F Humidity: 20 to 90% RH (no condensation) External dimensions Approximately 7 1/2 x 7 3/4 x 3 inches (W x D x H) Weight Approximately 3 pounds 28