You can use them unplugged year round and plug them in to the electrical outlet to keep water from freezing in cold weather. We have two Rubbermaid 70 gallon water tubs with built in heaters.
Excellent condition Aloka Model SSD-500 ultrasound machine with sony vidoe graphic printer. 5 mhz and 3.5 mhz probes. 1996 Aloka Modle SSD-500 Ultrasound machine with sony video graphic printer.