The Dogtra SureStim M-PLUS RX is the extra collar for SureStim M Plus Shock Collar so you can add up to 2 dogs to your system. This collar is fully waterproof and is ideal for small / medium size dogs over 15 lbs.
For dogs over 15 pounds
Range up to 1/2 mile
Low to Medium Power
Nick, Constant, and Non-stimulation pager vibration