Common, yes atleast in the ones I have talked with. It is good to purchase one for yourself. Especially for a pup in that they get puppy ADD and will do what they want and when until trained. I have a e collar on my dog all the time I am not out in my fenced back yard if I am taking the dog into the woods. I have a brittany and he has had an occasion to chase a deer, bear etc. I give him a hit to break his focus on chasing something I don't want. I rarely use my collar to shock but never know when the occasion should needed in the above mentioned circumstance. I don't advocate zapping your dog on regular basis.
