Also great for hard to clean fluids like resins and paints.  Made out of thick paper board.  Stores flat, dry and clean in a zip lock bag.  Folds up ready to use instantly.  Reduces the risk of contamination.  They   are 7" tall, the big opening is 2 3/8" square and the small opening is 1/2" square.  Sold in 10 pack bags.