carbon fiber rectangular bar stock

I’m looking online to see if anyone knows where i can buy some 1/4" x 3/8" rectangular carbon fiber. Usually this stuff comes in various lengths of like 12", 24", 48" long.

If it’s not exactly 1/4"x3/8" that is ok. Just need some online links to check out.

Thanks

I remember seeing tubes and stuff like that a while back on cstsales.com or something like that(can’t remember the exact address), but they have really high prices…