Motocross Tuff Blox Info for Sliders

Does anybody know who makes or where I can find out info on the Tuff Blox that the Supercross uses instead of hay bales? I'm thinking that if they weigh enough, they might work for building a rail jam slider pool. Any info would be appreciated. Thanks.

In-Line Sports Systems makes them.

Do you have any contact info for them?

dave after watching the supercross race tonight thos things dont look like they weigh a whole lot but it would be cool to see them used for the pools

Wow, I think this is the first time my beloved discussion board has failed me!!! Nobody's got the Tuff Blox 411???

I do, but I'm not telling...

Dave, I tried looking up their details but cant find it anywhere.
There's gotta be more than one company that makes them though?