Product width: the total width of the lattice surface of the belt is 5.0cm, the width of the elastic belt reflective strip of the belt is 2cm, and the waist circumference is 79-90cm Product design: anti-skid buckle for adjustment, three gear luminous switch, elastic band, retractable reflective strip, USB charging luminous Applicable sports: running, night running, cycling, mountaineering, various outdoor activities Product luminous mode: flashing - normally on - off Product battery: the product has its own rechargeable battery+USB charging cable, without charger Product features: This model adopts the design of widened reflective strip, which improves the safety during night sports. It also adopts the telescopic function, which can adjust the size, so that you can find a comfortable rhythm. In the title and description we have provided details of the product including its features and specifications, please note the size and dimensions of the product to ensure it meets your needs. Warm reminder: Due to lighting effects, monitor brightness, manual measurement, etc., there may be some slight differences in color and size between photos and actual items. Sincerely hope you can understand. During the shopping process, if you have any questions, please feel free to consult us, we will reply to you within 24 hours, I wish you a happy shopping!