Hi,
Today I'm sellingy Zenitco (genuine) b-20u handguard which is made for a RPK light machine gun.
It's been mounted on my ghk rpk and has never really seen the field (as I had a lot of trouble making this freaking rpk work well) so it's in a really great condition (see the pictures).
It's a really cool handguard, with a picatiny rail on the bottom and basis slots on the sides and at the 45° angles. It's also really light (as it's made from d16t aluminum as for all Zenitco parts).
Works perfectly for a ghk rpk, I don't know for the other brands.