The HT Heat Tech Vest features Alpinestars Heat Tech System which distributes perfectly balanced warmth in the coldest of conditions. The smart system has a double system for optimum performances in cold weather, a manual control through a LED button with three pre-set heat setting & an automatic heating control system. Features The automatic heating control system has a temperature sensor embedded inside the vest to continuously check the rider’s body temperature in order to provide & maintain the pre-set heating temperature for supreme riding comfort Smartphone Alpinestars Heat Tech App (same than Alpinestars Heat tech gloves) for turning the vest ON/OFF & to set & control the internal temperature through a Bluetooth® connection. Dual power: the vest can be plugged to the bike battery or used the included high performance 12v Lithium Battery for reliable, long-lasting power to the Alpinestars Heat Tech System Alpinestars Heat Tech System features superior Graphene heating panels which ensure greater efficiency & heat distribution, as well as being more breathable, flexible & robust over time The four heating panels are placed strategically on the chest, lower back & back of the neck for optimum heating performance The vest is made from a mix of soft materials (polyester/stretch) for rider comfort Front closure has an asymmetric angled zipper to reduce bulk under other layers On the right bottom side there is a pocket where the battery can be stored On bottom right side there is an extension with a visible button to activate the heat system Internal fleece soft panels cover the Graphene heating panels Rear adjustable length for an optimized fit Reflective prints on back & front