[JoeyP]

OK .... be careful here
because many of these collars work on the ... giving the dog a shock principle to stop them from barking
whether it is an actually electric shock or a loud noise ...they can be stressful or even abusive to the dog

There are tried and true ways to stop barking and there is even a sticky post on the subject here in the forum

I have a barker myself ....and Yorkies in general are vocal dogs they tend to be barkers
What I did and it takes some time .... is never allow you dog to continue barking when they get into that barking jag it's hard to get them out of it
Whether you clap your hands .... yell stop... or No Bark
make sure they stop and look at you
You can even use a water pistol if that works.... but be careful I tried that and it scared the hell out of my dog

but be wary of the collar thing
many of them are not good for dogs