Transformer controllers RT .. are designed to change motor rotating speed by changing voltage. Regulator is with transformers thermoprotection function. Steps are with fix voltage and are changed with rotary switch. To one controller more than one motor can be connected, if total current of all motors is less than maximum controller current. This appliance is not intended for use by persons (including children) with reduced physical, sensory or mental capabilities, or lack of experience and knowledge, unless they have been given supervision or instruction concerning use of the appliance by a person responsible for their safety. Children should be supervised to ensure that they do not play with the appliance.