One word.....Innot
ek.
We got an Innotek system when we bought our house. It worked wonderfully. For years those collars got punished out in the 5 acres of mud, snow, dirt, grass, and muck of our yard. The collars were a bit scuffed up but still worked like new. They are sturdy products. The main transitter unit died an early death because I did not purchase the lightning surge protector. It was out of warranty and a replacement part was not available. That was this past spring. The collars were still perfect and I sold them on Ebay.
I decided to cheap out and buy a different brand of fence system off of ebay. Not a good idea. We've been using the ebay system since midsummer. It's rechargeable. It handles 3 large dogs and covers 5 acres. That's about it for similairities. It's cheaply made and doesn't hold a charge for very long. The batteries have to be removed from the collars for recharging. I have to use a knife to twist the covers to get the batteries out. Each time leaves a mark on the battery cover.

This has to be done every 2 weeks even though the dogs rarely trigger the signal. The batteries don't hold the charge.
Hello Innotek?
Our new system arrived a week ago.
Some of the reasons I selected this system:
Rechargable collars. No batteries to remove. Just set the entire collar on the charger and a dead collar is recharged in 2 hours.
Some rechargeable require you to remove the batteries for recharging.
Not fun with 3 dogs.
ready light on collar shows when it needs to be recharged
Collar tells you that it's on the dog properly.
24/7 battery backup
The following is copied from the site because I couldn't figure out how to explain it.

Patented Run-Through Prevention
Run-Through Prevention is a feature patented by Innotek. It is only available in Innotek systems. In the past, systems offered only one level of static correction. This caused two problems. First, dogs would would only have to withstand one level of stimulation as they ran straight through the boundary. Second, dogs that accidentally walked into the boundary were hit with the full correction.
Run-Through Prevention has solved both of these problems by creating a zone of increasing stimulation. You are now able to set the distance before the boundary at which the stimulation begins. So if you set the containment field at 10 feet, an audible warning tone will occur, giving the dog three seconds to return to the safe zone and avoid stimulation. If the dog does not heed this warning tone and continues on, the stimulation will begin and will steadily increase as the dog approaches the boundary. This has solved our two problems. First, dogs must now run through a zone of increasing stimulation instead of just one correction level, making it much more difficult to escape the containment area. This progressive correction never lets the dog know where the boundary wire is, so he thinks the stimulation will never end. Second, Run-Through Prevention is more humane because your dog only receives as much stimulation as is necessary for him to retreat to the safe zone. Systems without Run-Through Prevention are not as humane or effective.
Hope that helps.
-Wendy
PM with questions if you like. Honest....I don't sell for Innotek or own stock....I just love it. I did my research on this one.