The wireless system you can have as many dogs on it as you want and the way it works is it you will have a base transmitter plugged in on the window in a large room in your house pointing out in the direction of where you want to give the dogs the most room
Once the dogs stay within the signal of this base transmitter they are in their safe zone and if they try to leave it it will give them a correction.
The wireless system has a minimum operating recommended radius of 50 meters so wherever you have the base transmitter plugged in you must be able to allow your dog 50 meters in every direction from that point in a rough circle
The GPS system is a standalone unit and it's only an electronic unit that your dog wears on his neck
This unit connects directly up to satellites and the way you set it up is you stand out in the middle of your garden in an open area and set the item to connect to the availability satellites in the area and the minimum operating radius is 30 meters on that item meaning that from this exact point at the minimum setting you must be able to allow your dog 30 meters in every direction
Basically the GPS system is a standalone collar that your dog wears which connects straight up to the satellites in the sky. What you do is stand outside in a very open area and set this as your centre point letting the unit connect to the satellites. Then you can program in the distance you require and the minimum distance is 30 m in every direction all the way up to 1,000 m.
With the wireless system, this has a base unit and a receiver collar. The base unit transmits a frequency and your dog has to wear the collar and stay within the range of this frequency
Normally what we would suggest is that you have to base transmitter on a very large window pointing out in the direction where you would like to give your dogs the most room, from the base unit we would recommend the minimum operating radius as 50 m meaning that you should be able to allow your dog to go 50 m in every direction as the minimum setting all the way up to a thousand metres