Same as model RT-1 Express Train system but with 2 receiver collars for simultaneously commanding 2 dogs with a single hand held trainer. New Express Train is an advanced remote radio dog trainer that quickly teaches dogs multiple behaviors with High Tech Pet’s proprietary Command – Tone – Stimulus training system. Three positive training tones may be activated at the collar. These tones are associated with positive commands such as “Sit”, “Heel” and “Retrieve”. A negative tone is provided to command our dog to cease unwanted behavior such as digging, barking, chewing, etc.. The negative tone may be followed by one of four increasingly intense static stimulus levels if the unwanted behavior persists. No other electronic trainer provides such a complete and comprehensive training system. One half mile range. Includes hand-held transmitter, radio collar , short and long hair probes and complete training manual. Receiver collar and transmitter collar are fully waterproof and operate on built-in rechargeable lithium-ion batteries. Commands up to 3 dogs with additional receiver collars sold separately.