PREMIUM MATERIAL & WEATHERPROOF: High quality PVC Leather and Nylon webbing make our illuminated dog collars more durable. Our light up collar is suitable for all weather conditions, i.e. rainy days, water splashes etc.ANTI LOST & AVOID TRAFFIC ACCIDENT AT NIGHT: Flashing dog collar helps spot your dog on snow-covered streets, in the forest or on the driveway at dusk. Our dog collar light helps vehicles on the road spot your dog enhancing your dogs safety at night.3 LIGHTING MODES: You can set the LED dog collar light in three different flashing modes, i.e. Quick Blink, Slow Blink & Steady Light with ON/OFF button.3 ADJUSTABLE SIZES: Our dog light up collar available in 3 sizes. Medium size range is 40.6cm 48.3cm / 16 19 (inches). NOTE: Adjustment is not limited to black nylon adjustment area, but collar can be shortened up to PVC leather area to get desired size as shown in video.USB RECHARGEABLE: Easily rechargeable USB battery (150mAH) lasts more than 8 hours (charging cable included). NOTE: Please charge battery for at least 2 hours before first use.