I remember using this 20 years ago. My 4 1/2 yo lab has been collar wise since the first HT. She get out of her box and shakes to see if the collar is on. So....at the last training day I installed two e collars, used the choker as i always do in the holding blind. On the last holding blind I removed the choker and also the dummy collar. She did the shake and felt lighter and thought the collar was off. I have trouble with her breaking at moch 10. this time when she started to get loose I gave her a good correction. maybe in a few week i can get back in the games.