Although your actual delivery service was great, I was not informed about the requirements for the correct size magnet for my dog, only the collar size. My springer is a large springer but has a small neck. As I understood the collar needed to filter close to the skin I ordered the exact size for her neck, on arrival the collar looked very narrow but I assumed this must be right, when she didn't show any improvement I read further reviews etc and it seems the magnet size may be too small? I feel I should have been given better information and would have preferred to spend more on the correct size collar rather than waste money on one that does not have any effect.