I bought this device after reading many reviews, which cited excellent customer service, and easy replacement of 9V battery. I have two dogs, and when I went searching for an extra collar with the 9v battery, I was told they stopped manufacturing them and would have to purchase rechargeable. Rechargeable is fine when new, but I have a closet full of devices with discontinued dead rechargeable batteries. I would have preferred the 9v option, but I bought the current model. SportDog FAQ mentioned 14 gauge wire could be used, so I ordered 2000 Feet of that for my 3 acre lot. I paid $45 to rent an edger that included a spool to feed the wire into the 2" mini-trench. Took one day to bury the wire, and another day to finish places where the wire popped out of curves. In hindsight, should have provided more slack as we pulled. I don't see how 20 g wire could have stood up to the tension, but maybe that was just the way this machine was set up. I incorporated four splices, and the (2 only) provided gel-filled capsules worked great. As I said, I used 14 g single strand dog wire. The most frustrating thing about the installation was the cheap terminal connectors. They just would not grip the 14 g wire! I had purchased the surge protector, which had similar terminals. I can understand space restrictions on the surge protector, but why not allow the option of screw terminals on the transmitter? I worked around this "fault" by using 16 g stranded speaker wire which I connected to the surge protector. Even then, I had to rig some clothespins to keep enough tension on the springs to grip the wire. I must tell you, going through my mind were conclusions that this whole device is made as cheaply as possible, and the manufacturer is making a huge profit. But good customer service costs money, so I will forgive the hefty price. The two manuals that came with the product were very thorough, helpful, and educational. Five stars for documentation. I've got 1500 feet of wire underground, solid connections, flags every ten feet. One dog is wearing the collar for the first day, getting used to the feel of the device. Tomorrow we start with lessons. I am optimistic. Will update review in a few weeks to report the effectiveness of the containment, and the training remote. **** UPDATE It is now a month later. I took my time getting the dog used to wearing the collar. We attached the module to a clip on collar., It was very easy to remove the buckle-strap and attach the module to the clip-on, though we did have to cut and re-sew the strap. The first day I activated the system, as recommended, I set the collar at contain + train, strength #2. A few minutes of training as directed in manual, worked okay. Later in the day, my daughter did a training session and she reported the dog failed to react. I decided the collar was too loose, so next day I tightened it, and I increased the power to #3. Well, the improvement was dramatic and the learning by the dog was QUICK and EFFECTIVE. We started at the same flag as previous day. Dog was attached to leash. I pulled her back when she gave a little yelp, and pointed to the flag. We walked 100 feet to another flag. Same process. Same reaction. She was more wary. We walked another 100 feet. This time she pulled the leash out of my hand when she hit the shock zone and she ran across the line. This gave a longer exposure to shock, and she yelped loudly, running right back to me. I pointed to the flag. SINCE THAT MOMENT, THE DOG HAS NOT COME WITHIN FIVE FEET OF THE FLAGS, with or without the collar in place. Containment training complete! Amazing. ** Now, for the training remote. We are the fifth home of this nine-month old rescued dog. We have had her two months. Previous owners described her as "too much dog". She wants to bite like a puppy, not mean, but very mouthy. Before we got the nine-month old dog, we had also rescued the much smaller, dog who at the time was only 8 weeks old. Truly a puppy. But a little fireball who, as she grows, wants to play with her bigger, mouthy, companion. The training remote has been very helpful in teaching the bigger dog to play gently. The older dog also mouths people when she wants to play with toys. I almost always leave it in "V/T" mode, which is vibrate/tone. The dog associates the tone with the shock of the containment line, so all I need do is "tone" her and she gets the idea. Every once in a while, she tests our patience, and we vibrate the collar with instant results. I have spent many hours teaching her verbal commands and tried to use the training remote to supplement; however, no amount of verbal seems to keep the dogs from engaging in puppy biting and play. The training remote has been the key to preventing the older dog from harming the younger dog. Tremendous progress with both dogs, with two people holding leashes and myself toning the bigger dog to remind it to be gentle, when necessary. I will still keep my overall review at four stars, due to the flimsy construction of the terminals. I would rate the practical side of containment and training at FIVE STARS. ** The module is big and bulky. I wish it was smaller. I also wish there was a variation for smaller dogs. My little puppy is only 7 pounds, so I have not used the collar on her; however, now at almost four months, she wants to go hunting. I keep her on the leash, and try to make her respect the flags, which are still up. I think she would also learn to respect the boundary very quickly if there was a training containment collar available for small dogs. ** I am very satisfied with this purchase. I have been working diligently with a very difficult dog, and I believe the SportDog contain + train unit has helped tremendously.