it's a buggy tire. here's where i buy all my treaded pre-mounts:
http://stores.shop.ebay.com/Supra-Sales__W0QQ_armrsZ1
the thing i like about this store, is all their pre-mounts are always perfectly balanced and they are glued very very well.
I've used the fishing line method on these as well and it works great:
http://cgi.ebay.com/Yoko-1-8-pre-mou...4.c0.m14.l1262
I think, ideally, the HPI phaltliners are the best for the truggies/MT's, but if traction is an issue for you like it is me then the Supra truggy yoko's are great with the fishing line technique.
also, i've heard mixed reviews on these, but might work for MT foams. it certainly has the size. i just don't know how good the glue is.
http://www.imexrc.com/servlet/the-25...M-GREEN/Detail