b'OPERATIONControl is via a simple button. Temperature is indicated by an integrated LED light thatCREATIVE NANO CARBON TECH changes colour to preset levels.The heart of our system. The advanced conductive thread heating technology is sandwiched between two protective materials and is both washable and safe53C / 127 Fas per instructed. Red light indicates highest degree of heatHEATING ELEMENTS 48C / 118 FPurple light indicates We have hidden the system in the jacketthird level of heatlining at the back, so you can play warm and with style43C / 109 FPORTABLE BATTERY Green light indicatessecond level of heat Simply plug the USB cable into a portable 5V, phone charger battery.(Battery not supplied). 38C / 100 FWhite light indicates lowest level of heat9'