[atkins72]

My female is 15 weeks and 29lbs. We are using one on here. It works very well and after a few days it only takes a light jerk or two to get her attention. She is heeling very well and it helps to reinforce sit. My dog is very aggressive for a female and fought it hard the first two times. After a good whoopin, and I use that loosely, she learned that fighting only makes it worse.