I had a 4' chain link one time- it was in good condition, but my bitch pointer came in heat and before I knew it every male dog in town was coming around. My brother-in-law said I got just the thing. He told me to pick up a roll of wire long enough to go around the yard and some wood stakes. He brought over an old transformer out of a neon sign he salvaged. I staked that wire around the yard, and we hooked each end to that transformer. It was frying everything. He said don't worry its only about 1 amp. I say o - ok. Later I decide to look at the tag on that thing- output was 1 amp but 10000 volts. One day I could hear a dog squealing and went running out there- a little Scottie has got on it and was just paralyzed on the wire. I jerked the plug out and he started jumping about 5' in the air trying to get out of there.