Washington State Personal Illumination Device (P.I.D.), Be seen and safe when out at night walking, riding, jogging. The PID comes in Round, Football, and Dog Bone shapes. Attaches using a Carabiner, 3 LED modes ( Flash, Strobe, and constant ON. ). Motion Activated Display Mode. Bright Light can be seen up to 200 yards, replaceable Battery, durable. One Unit Per Package. Add to your Backpack at the bus stop, your Bike, Hang from your coat zipper, key chain, leash, dog collar.