Kasablanka corporation manufactures various types of laboratory plastic products. This is an iso 9001-2000 certified company. Petri dishes are part of those products. These petri dishes are made of polystyrene and are transparent, crystal clear. The one time use petri dishes are fully sterilized at `isomed" mumbai. They are packed individually to preserve it from contamination. Dish and cover fit together tightly to prevent dehydration of media.