LED Lighted Pet Harness, 5 Colors (Black, Blue, Green, Pink, Yellow), 4 Sizes (Small, Medium, Large, X-Large), LED Lighted Harness Glows or Flashes for Extra Safety on Evening Walks LED lighted harness glows or flashes for extra safety on nighttime walks Easy to use - simply pushing the control button turns on, and then changes, the lights to FLASH FAST/FLASH SLOW/STEADY ON/OFF Bright LED lights can be seen from a good distance Power source: 4 each, CR2032 button batteries, included and pre-installed Please read sizing chart below, harnesses run on the small side but are easy for you to put on and take off of your pet, comfortable for your canine companion to wear