Home made, see this post a few post down: http://www.scubaboard.com/forums/zeagle/340536-inherent-buoyancy-express-tech.html
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Go to your local craft/sewing store and buy 3-4 feet of 2 inch soft webbing. add 2 sliders and voila- instant crotch strap that won't strangle anything important. Total cost for me was just over 5 bucks.