ScienceWiz - 50 x 15mm Sterile Petri Dish (Set of 20) AWARD WINNING ScienceWiz curriculum is designed to teach kids science in an intuitive and natural progression Explore the basics of biology with this set of sterile petri dishes from the award winning science experiment creator, Science Wiz Package includes twenty 60 x 15 mm sterile petri dishes These petri dishes provide the perfect container for bacterial growth and other fun science projects Intended to be parts for use with science projects, science fairs, etc. and are provided with minimal to no operating instructions