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 tops and bottoms which provide convenient grips for one handed opening. Their snug fitting tops ensure that neither the absorbent pads nor the agar media will dry out during incubation. A frosted area on the top of the lid permits labeling. Made of non toxic clear polystyrene.