Onebigoutlet 500 Yards LCD (2) Remote Pet Dog Collar Training E-Collar w/Vibration, Shock Electric Remote Training Collar with advanced 433.825MHz technology, range up to 500 yards. Can control up to two collar receivers and includes two collar receivers Both transmitter and collar receiver are rechargeable; 100% waterproof dog collar receiver Handy vibrate function allows the user to "warn" their pets before administering a static correction; Adjustable collar adjusts from 8 to 20 inches to fit small and large dogs Built-in LED light is perfect for dark environments 9 static shock levels is easily adjusted by the Up/Down buttons