brand name Derail maybe?(spelling?) they have a lot of stuff like that.

I have seen the tubes either way depending on the trans.

we ran them on the turbo400 pontiac trans,turbo350 chebby trans mostly.

they say right on the sales pitch not recomended for 4x4 use due to clogging.

IMHO, I would think one would keep them flushed out when running them on dirt roads/off road. I know I did.