If you think that Dog Guard invisible fences are only for Small/Medium/Medium-Large sized dogs think again.The fence keeps my 100+ pound Male Rottweiler Max (non neutered) in just fine.Yes he had his learning curve with training but since training was over he has not gone through the fence.It gives me piece of mind to know that i can let him out and that he will not wander.I live right across the street from a local High School so he always has stimulation from the other side of the fence.We try not to let him out during the real high traffic times (when school opens in the morning/closes in the afternoon) not because we are afraid he will cross the barrier but he can really scare the blank out of kids if they didn't know he was there. The invisible fence works so well that Max won't cross even if the collar is NOT ON..I have had friends try to coax him across with a fresh marrow bone/piece of meat and he will not cross.If you don't believe me you are welcome to come over and see. The best thing is in the 2 1/2 years i have had the fence i have never had to call Dog Guard with a problem.Dog Guard really delivers what they say they will.A well run family buisiness,customer oriented, and the Spain's are just nice people. Thanks again for such a great product Chuck Rosano __________________________________________________________________ >