Getting the right converter for this 110/120v device, where the power is 220/240v
Amps * Voltage = Watts. So 10 A * 120 V = 1200 W. Alternately 5 A * 240 V = 1200 W. So you need a transformer or converter rated for 5 A on the 240 V side and 10 A on the 120 V side.