Dog-E-Glow Texas Christian University Horned Frogs Lighted LED Dog Collar, Medium, 10-Inch by 15-Inch Steady glow and flash mode 150 hour replaceable battery life 100,000 hour LED life Fully weather-resistant, visible up to 1000ft in the dark Batteries included and replaceable batteries also included (Four 2032 3V lithium coin cell batteries)