"I bought one of those little vest looking harnesses for our first two ferrets. They look like life-jackets with buckles and velcroe on them. They were a total waste of money. We got two of these from someone that got rid of their ferrets. They are AMAZING. Not one of our ferrets got lose wearing one, and I can safely run around the yard with our three girls, not worrying if someone is going to slip their harness. The only reason our one girl Saya does, is because she is very slender and on the small side. Our other two are standard sized female ferrets, and neither get lose. They love them, and don't seem to bother them at all. I highly recommend them to any ferret owner."