1Heating and Cooling: Adopts semiconductor plate cooling and heating, three speed temperature adjustment. Cooling mode in summer and heating mode in winter, ideal mobile AC for going out, office, study, camping, travelling, hiking and other activities can be carried with you. 2Ergonomic: U shaped around the neck, in line with the characteristics of the human neck curve, fit the neck, according to the size of the neck can be adjusted to open the distance between the two ends of the fan, fat and thin people are suitable for more comfortable to use. 3Quiet: Neck AC adopts permanent magnet frictionless engine core, reasonable wind channel design, the noise is effectively controlled below 30dB, even if you use it at night, it will not disturb your rest or work. 4Large Capacity Battery: The fan has a built in 3500mAh high capacity lithium battery, which allows the neck AC to work continuously for 1.5 to 3 hours under full charge. Ensure you have a lasting cooling experience, no need to charge frequently, enjoy the cool time. 5Opening Width: The two ends of the cooler and warmer are connected by soft silicone, and the maximum opening width can be up to 31.5cm, which is also suitable for people with fat figures, so you do not have to worry about not being able to fit it or wearing it uncomfortably due to the size limitation. Item Type: Neck Fan Material: ABS, silicone, aluminium, stainless steel, electronic components Battery: Built in lithium battery 3500mAh Size: Approx. 17 x 4.4 x 14cm / 6.69 x 1.73 x 5.51in Maximum Distance Between Both Ends Open: Approx. 31.5cm / 12.4in Input Voltage/Current: 5V/2A Charging Time: About 2.5h Use Time: 1.5-3h (depending on the environment temperature.) Cooling Mode: 25C, 20C, 15C Heating Mode: 30C, 35C, 40C 1 x Neck Cooler Warmer 1 x USB Charging Cable 1 x User Manual