EcoLite’s environmentally friendly built-in rechargeable power pack lasts up to 25 years. Now you’ll never have to worry about running out of costly batteries. It’s incredibly small and lightweight, weighing just under an ounce. EcoLite’s small size makes it the ideal choice for small dogs. But, just because they’re small doesn’t mean we crimped on features. Each receiver has a full range of programmability, including GentleSteps™, Pet Stop’s® exclusive training approach that reduces stress and makes training easy and effective.