Ematech Cooling Jacket. Material: 65% polyester, and 35% cotton. The high power fan is possible to concentrate the airflow toward the back and chest. Lithium ion battery and charger have acquired PSE certification, safety for user. One set of Cooling Jacket includes: one jacket, one battery, two fans, one 3-way cable, one charger and one charging cable. A hear stoke countermeasure product for people who work in environment where air conditioners can not be used such as factories and outdoor works in the hot summer. This jacket may help to keep your body fresh and comfortably even in a high temperature environment and improve work efficiency. Do not hesitate to have it. Be fresh yourself.