Which type of caps could be these???

[bancika]

I got some caps from local electronic supply store but I'm not sure which type they are. They call them "Block", and it's certanly not ceramic. They look exactly like these WIMA foil caps , except they are yellow and nothing is written on them except for value. I think I saw those in my Marshall jackhammer (not DIY). Any ideas which type they are?

[phaeton]

I want to say mylar.  At least, I have a bunch like that too, and they act like mylar.

I dig em.  they're excellent for breadboarding.  I wish I knew where to find the whole litany of values in those.

[KORGULL]

Sounds like the yellow AVX polyfilm box caps I get from Digi-key: http://www.digikey.com/scripts/DkSearch/dksus.dll?Detail?Ref=244532&Row=228599&Site=US