► There is no official warranty. But if got any problem you can let us know and we will liaise with the supplier to come up with the best solution for you. ► Can be washed and reuse multiple times. ► Size L is suitable for men. ► Size M is suitable for woman. ► Size S is suitable for children. ► Please refer to chart for more accurate size measurement. ► 1PCS Xiaomi Smartmi Anti-Pollution Air Sport Mask. ► Comes from Xiaomi Eco-chain. ► Skin-friendly Soft memory TPU, Free to breath. ► Filter out air dust, PM2.5, Haze, pollen grain, automobile exhaust. ► With the ventilating valve, the mask is safe and comfortable to wear. This new anti air pollution face mask was launched as part of Xiaomi Eco-chain products. It can effectively blocks dust and PM2.5 particles at outdoor especially during haze season. With its adjustable ear hanging 3D design and ventilating valve, it is comfortable to wear for long period of time without feeling of suffocation for both men and women. The face mask material is made from breathable TPU while the air filter is made from nano-fiber with electret filtering technology which is capable of filtering PM2.5 particles with efficiency of up to 97%. Please note that this item comes from Xiaomi Eco-chain Cooperation, so there is no Xiaomi logo on it. Specification:  Brand: XiaoMi  Color: Dark gray Material: TPU  Type: Filter Mask Filter efficiency: >=97% Suited people: adults Wearing way: ear-Wearing Product size (L x W x H): nose to ear19.5 x 13.80 x 0.5 cm / 2.95 x 5.4 x 0.2 inches  Product Weight: 16.9g / 0.59oz Package size (L x W x H): 20.00 x 5.00 x 2.00 cm / 7.8 x 1.95 x 0.78 inches Package weight: 200g / 7oz