Two-dog mode allows the trainer to control two dogs from one transmitter. Power saving design with automatic standby and memory function. With memory function, if the transmitter and the receiver do not run out of power, the product can work by just turning on the transmitter and the receiver.In other words, there is no need to pair them again in such case. No external antenna on the collar receiver. Unique built-in antenna in the market. This collar is ideal for small medium and big size dogs. We are not responsible for any wrong or undeliverable addresses. Please verify your address during checkout. The item "800 Yards Waterproof LCD 2 Dogs Shock Training Collar With Remote Rechargeable US" is in sale since Sunday, April 24, 2016. This item is in the category "Pet Supplies\Dog Supplies\Training & Obedience\Electronic Fences". The seller is "goodscity2010" and is located in Springfield, New Jersey. This item can be shipped to North, South, or Latin America, all countries in Europe, Australia.