Grow mold, germinate seeds, observe objects with a magnifying glass, or trap a bug. Hundred of uses with these deep set plastic petri dishes. The Petri dish 4-pack is a great addition to the Science Accessory portion of your Science Center . Four empty petri dishes, 100mm x 25mm , activity guide and pipettes includedScientific Skills: Experimenting, Observing, Predicting, Drawing Conclusion, Exploring, Investigating and Communicating.