ITERY Dog Collar, Led USB Rechargeable Pet Safety Collar Waterproof Light up Adjustable Flashing Collar Three flashing mode: The Led dog collar can be set to quick flash, slow flash or light continuously by pushing the button. Adjustable dog collar: This flashing dog collar is adjustable-can be cut to any length to fit your pet. The length of the collar is 27-1/2 Inch. Rechargable pet collar: No need batteries, and can be recharged by the USB cable with any other daily use device, e.g. computer USB port or smartphone Chargers Waterproof dog collar: waterproof function, can be used in raining days. Safety dog collar: In low light conditions, This dog collar can help you keep your dogs safe.