ion one stroke flat iron 1 1/5 inch ion the ion one stroke perpetual heat flat iron straightens hair in just one stroke without excessive, damaging heat. powered by tsc - temperature sensor circuit, a revolutionary new, electronic heat sensor technology that reaches operating temperature in just 45 seconds and generates phenomenal and accurate heat stability with an unmatched heat recovery time of only 6-8 seconds which virtually means a constant operating temperature with minimal drop off from roots to ends. with tri-layer heaters, tsc sensor circuits are embedded directly into the layers and read real-time temperature across the entire surface of the plate. as the heat from the plates is transferred to the hair for straightening, the tsc sensors simultaneously trigger more power to the plates to recover optimum temperature to the entire plate surface in just 6-8 seconds.