[Safe Effective Humane 3 Training Modes — Redmogo shock collar for dogs offer customized Static Shock (1-99) and Vibration(1-99) levels. These variable stimulations can be tailored to your dog’s temperament while the adjustable nylon collar fits 0-27 inch in length. Shock collar with 2 receivers — The training collar set has two receivers you can train your 2 dogs with one remote control at the same time freely. The training collars are perfect for people who have two dogs. Indoor & Outdoor Versatility — The remote for this dog training collar can reach up to 3000 feet allowing you to train dogs in the backyard the park or anywhere else. Premium Ergonomic Design — The easy-access button sizes and simpler format are easier to operate for pet owners and help dogs learn commands more effectively. A premium training collar for expert trainers and new pet owners the conductive silicone prongs are also safe on coats and skin. Rechargeable Waterproof Durability — This collar receiver allows your dog to play in the rain or wet without removing it. But please take off the collar when swimming or playing in the water. Each dog shock collar boasts Lithium-Polymer batteries that charge in 2-3 hours and last 15-20 days.]