>>627575pic related is what I have.
The point of the design is that the bears can't pick it up and run off because of the angle and can't bite into it. There are other ones out there and I'm sure you could find one on ebay, but please don't think that making your own is a good idea, since it will likely get you into trouble with park services and bears are a lot more clever than you think.
A lot of study of bears went into the design of these things and that's why they are required in a lot of places instead of bear bags.
