The Dogtra SOUNDBOX2 is an effective tool for instructors to demonstrate to students in training sessions when and how much stimulation to apply to their dogs. To begin, simply pair your Dogtra handheld transmitter with the SOUNDBOX2. Once paired, the SOUND BOX2 will make a beeping sound when the stimulation is applied and held down, becoming louder/quieter as the stimulation level goes up/down. The SOUNDBOX2 efficiently teaches students the level and duration of stimulation needed in different scenarios that the dog may come across. This compact and valuable training tool will be a great addition to your training session. Compatible with the iQ PLUS, 200C/202C, 280C/282C, ARC, ARC HANDSFREE, ARC WETLANDS, 1900S/1902S, 1900S HANDSFREE, 1900S WETLANDS, 1900S BLACK EDITION, EDGE, and EDGE RT.