The PRO 550 with proven Tri-Tronics® technology allows advanced training for the serious professional with easy access to 21 levels of momentary and continuous stimulation, tone as well as the ability to quickly switch between 3 dogs¹. PRO 550 features vibration and tone settings, remotely operated beacon lights on the dog device to help locate your dog in low light, the ability to add an Upland™ Beeper (purchased separately), and a built-in BarkLimiter, activated on the dog device, to help keep the peace at home.