Penn-Plax American Red Cross LED Nylon Dog Necklace will boost your dogs visibility after dark. With 360 degrees of illumination your pet will easily be seen no matter how dark their surroundings. Cut to size for the best fit without damaging the interior LED lighting.Contains a USB rechargeable LED bulb with 3 settings and reflective stitching. The 3 light up modes include a fast flash, slow flash or constant on. Micro USB charging cable included. Can be worn over existing collar.