These 50 x 9 mm sterile petri dishes with absorbent pads are ideal for culturing micro-organisms on either agar or broth based media. Designed to accommodate 47 mm diameter membrane filters. These dishes are stackable and have squared off edges on both the top and bottom which provide convenient grips for one handed opening. The snug fitting top ensures that neither the absorbent pad nor the agar media will dry out during incubation. A frosted area on top of lid permits labeling.Made of polystyrene.