Cool-Space CS5-16-VD CS-16-VD Variable Drive Portable Evaporative Cooler, 18-Inch The COOL-SPACE 18" variable speed, direct drive is completely portable with a thick, UV resistant housing that will not leak or rust A large 16 gallon built in water reservoir offers hours of operation without a water supply connection Edge coated cooling media for durability and exteneded life. Fan Motor : High efficiency, totally enclosed. 75hp /110Volts /60Hz. Variable Speed Longest warranty in the industry!