Really good collar!
We bought the Big Dog Rechargable Bark Control Collar for our Wolfhound X with extreme seperation issues. He has to be on a tether because he jumps the fences so he barks and howls constantly for us :( first time using the temperament learning mode and he barked 3 times and that was it. No more howling, no more barking. Instead of worrying about him becoming 'collar aware' we are making it obvious that his new 'zappy' means no barking as we only use it for when he's left alone. It's working amazingly he knows he can bark his head off when he's not wearing it and he actually settles when left alone now instead of constantly barking and frothing at the mouth with stress. Highly recommended the collar itself and barkcontrol.com.au great prices, fast shipping, and heaps of easy to find info.