Contents ・Speed Heat (Ladies) M size, with battery ・Dedicated batteries x 2 "One extra battery that is not originally included." Material Composition Outer: 100% nylon, Inner: 100% polyester, Filling: 100% polyester, Sides: 95% polyester, 5% polyurethane Care Instructions Hand wash only About this product The fiber heats up when the power is turned on, quickly warming you up in about 15 seconds. The fabric is made of nylon, which traps heat and prevents warmth from escaping. The side stretch material makes it comfortable to wear. It's thin enough to be used as an inner vest. With a single switch, the neck, back, and waist can be warmed in three places. The battery can be removed and hand-washed at home (the battery jack needs to be covered with a plastic bag). Product weight → Approximately 440g including the battery. Monthly electricity bill → 41 yen per month for 3 hours of use per day (Chubu Electric Power). Uses micro carbon fiber. ⑤ Product weight → Approximately 500g including the battery. ⑥ Timer function → None. ⑦ Monthly electricity bill → 34 yen per month for 3 hours of use per day (Chubu Electric Power). ⑧ Uses micro carbon fiber.