Bluecollar if you value your ferrets and intend to work them I'd say there a must have, not only do they help you keep a track of them within deep undergrowth and warrens, preventing loss, they also help if a ferret kills in with a rabbit or lays up with one, this can save a lot of time, preventing you from waiting around, the last thing you want is to be hung around a warren for hours waiting... I wouldn't leave the house without one, they help you move from one warren to the next in no time, I have a strong hob who kills in 9 out of 10 times if he can, without a locator I'd be hung around, t