Garmin PRO 550 Handheld Top-mounted selection dial is for Vibration and Stimulation Levels (1-7) Green button operates Tone and any compatible accessories, like the Upland Beeper -Toggle switch selects which dog is being controlled (up to 3: black, red or blue)-Toggle switch FORECAST(M and C selects stimulation type and A is for Accessory Upper black button selects medium level of stimulation (1-7), and turns Lights on. -Lower black button selects low level of stimulation (1-7), and turns Lights off. -Pressing both black buttons at same time selects high level of stimulation (1-7) Includes - PRO 550 handheld, AC adapter, manual