I've used them extensively in Africa. The set I used was purchased at Long Grass Outfitters, www.long-grass.com . They are made of red oak, and come in two sections for packing. A metal ferrul connects the sections, and the top is wrapped with leather.

No matter which shooting sticks you use, lots of practice is required, as they do take some getting used to. But, after you're comfortable with them, your groups shrink amazingly. I can comfortably place 5 shots in a 4 inch circle at 200 yards with them.