7 AC variable frequency drives that are used to control small and medium-sized motors in applications such as manufacturing processes, HVAC and pumps; Aerating pumps for aquaria; Air distribution units for pneumatically driven pumps; Air pumps for hydroponics; Circulating pumps; Compressed air pumps; Drives for vacuum pumps; Electric knife sharpeners; Electric pumps; Pneumatic pumps; Pumps and compressors as parts of machines, motors and engines; Pumps for machines; Rotary pumps; Water aeration systems comprising water pumps, air compressors and air blowers; Windmill pumps