Free-size cool vest with instant cooling at 28°C and heating at 39°C. Comes with two batteries. Used twice in August this year, for a total of about 10 hours. Both batteries were only charged once and are almost new. Beautiful condition! - Model: PRO model - Functions: Instant cooling and heating - Size: Free size - Cooling temperature: Instant cooling at 28°C - Heating temperature: Instant heating at 39°C - Battery specifications: 1.5V, 2000mAh - Power supply: USB, DC 5V/2A - Operation modes: ICE and HEATER modes Thank you for viewing.