I have used a ecollar for recall. It's a great way to teach your dog to come when they would rather go chase the deer or bunny while off leash. For retrieving I think the Labrador dog people would be the people to consult. Rottweilers are NOT retrievers, and honestly I would not try to mold one using an ecollar. Of all of the Rottweilers I've owned they were never too interested in chasing after a ball or item and bringing it back. I think at the most I could get them to fetch maybe 3-4 times and then they got bored. This is a protection guardian breed...not a retrieving breed.