Warnings:1. The snorkeling mask is for snorkeling only, please don't dive into free diving,scuba diving or strenuous swimming.2.Not suitable for children under 14 years and must be strictly under parent supervision only .3. Just leave it dry naturally after cleaning mask with fresh water to avoid direct sunlight and use glasses cloth to clean the face lens, don't use towel.Material: high quality silicone + PCSize: S-M, L-XLClose your mouth and measure the distance between the bridge of your nose and the bottom of your chin:If the size is less than 12 cm (4 3/4"), please choose the size S/M (most suitable for teenagers and women)If the size exceeds 12 cm (4 3/4 inches"), choose the L/XL size (most suitable for adult men)Color: black, blue, red and grayWide range of applications: very suitable for diving, swimming, snorkeling and other underwater sports[package]Snorkeling mask×1Minor errors may occur due to manual measurementUsers need to receive diving training, have safety knowledge and ability, and choose safe waters and appropriate depths. Recommended for diving activities and accompanying professionalsFull Face Snorkel Mask|Easy Breathing Snorkeling Mask| Swimming Diving MaskHow To Wear Snorkel Mask:1. Install the breathing tube on the snorkel mask.2. Install the removable action camera mount on the tube, then fix the camera tightly on the mount.3. Put on the mask and adjust the length of the elastic bands, please make sure there is no gap between the mask and your face.What size should I choose for snorkel mask ?Step 1. Measure the distance between the bridge of your nose and the bottom of your chin.Step 2. If the distance is 8-12cm, choose XS.If the distance is 10-12cm, choose S/M.If the distance is 12-14, choose Large/XL.