Static pulse, I think. He doesn't even need it anymore to be honest with you. We used it to keep him out of the dining room, he used it once and never went in again. My parents insisted on keeping it on for awhile. We have the things that shock him turned off.

This is not something I even knew about until they actually ordered it. I tried it myself, and it wasn't bad, it just caught me by surprise. He will be rid of it shortly.