EXPANDABLE DUAL DIAL: The T&B DUAL 2-DOG comes as a 2-dog setup, so the transmitter comes with two sets of Rheostat Dials that are dedicated for up to two dogs. With this expandable device setup, you won't have to keep changing the correction level for each dog and can seamlessly operate one or two dogs.PRECISE CONTROL: With 127 correction levels, you'll have no problem finding the perfect level for your dog with the gradual and precise control. The OLED screen is bright and easy to read while the levels can be adjusted precisely at any time with the two Rheostat Dials.1½-MILE RANGE: The range of this training e-collar is perfect for any and all simple commands for your dog. With a range of 1½ miles, this e-collar is a great choice for hunters looking to train their dogs in the field.CORRECTIONS: The fully waterproof T&B DUAL has two different correction types. The first correction type is a Nick (quick ½-second) and the second correction type is a Constant (up to 12 seconds). The e-collar also has an HPP (High-Performance Pager) which offers a clear vibration to alert dogs while training. Find the right fit for you and your dog with this dynamic e-collar.BEEPER MODES: The receiver has a unique single-body receiver/beeper horn to eliminate the bulkiness and enhance the durability. There are 3 beeper modes: Locate, Run/Point, and Point-Only, which gives you the ability to keep track of your dog. The Dogtra T and B dual is the advanced Dual dial training and beeper e-collar, designed for upland hunters.