I might be rockwool but I don't know for sure, sorry man. It looks like some sort of "just plant it in the pot and forget it" kind of deal though. (you prolly already knew that though)
Hmmmmm Rapid Rooter Plug. ive read about them but didnt know i had them. They just came in an unmarked ziploc gallon from my dro shop. To get off the subject for a second. has any one seen Deathrace 2000? if not Do It . its bad ass, i am watching it know. or any movie done by Ron Howard ,hes pretty badass old but badass