Leather Martingale Collar Sites?

Hey Everyone,
I am hoping some of you can help me find a good website that sells leather martingale (aka half-slip; limited-slip) collars? I want to find one for my pit-doxie mix Mojo. I've used a nylon martingale on him, and liked it except it wore his fur on his neck much more than his leather collar ever has.

Any help would be greatly appreciated.

Thanks!

~Megan

i know dogtack.com has one or two on their site. they also have ones made from mountain climbing rope, which is very soft and doesn't damage the coat. i've been using that kind for about 20 years and have been very happy with it.