Specifications: This vest is very suitable for men and women. Jacket has function of 3 seconds fast heat, 0 radiation safe, fast and smooth heating without radiation. It is ideal for family members, friends, employees, enjoying cycling, hiking, camping, fishing and other outdoor activities in autumn and winter. The vest is heated by USB and needs a 2A power bank (Not Included). Item Name: Vest Material: Silk, Spandex, Silk Floss Size Type: Regular Gender: Men, Women Style: Stylish Features: Warm Keeping, Zip Closure , with Pockets Size Details [Our Size M] Shoulder: 38cm/14.96", Sleeve: 10cm/3.94", Length: 60cm/23.62" (Approx.) [Our Size L] Shoulder: 40cm/15.75", Sleeve: 10cm/3.94", Length: 61cm/24.02" (Approx.) [Our Size XL] Shoulder: 42cm/16.54", Sleeve: 10cm/3.94", Length: 63cm/24.8" (Approx.) [Our Size 2XL] Shoulder: 44cm/17.32", Sleeve: 10cm/3.94", Length: 65cm/25.59" (Approx.) [Our Size 3XL] Shoulder: 46cm/18.11", Sleeve: 10cm/3.94", Length: 68cm/26.77" (Approx.) [Our Size 4XL] Shoulder: 48cm/18.9", Sleeve: 10cm/3.94", Length: 72cm/28.35" (Approx.) Notes: Please refer to our size chart and choose the right size. Due to the light and screen setting difference, the items color may be slightly different from the pictures. Package Includes: 1 x Vest