hmm.. it's a folder (enclosed like a zipped briefcase) with add-on sleeves inside. Usually you will see those BIG A2 size black flat folders carried by artists or art students. That's the one and they have various sizes.
I got one for presentation to clients. about 70 plus SingDollar. Also in S8R size
When you go to Bras Basah ArtFriend, once thru the doors, just look to the left. Anyway they are actually called 'folios'
cheaper way is to go to Popular bookshop and buy this clear holder file by DATABANK (FT-20) .. cheap and good. Fits S8R quite nicely. hehehe... but the clear holder plastic is quite flimsy on the touch...