Celltreat Scientific Products, 229663, 60mm x 15mm Petri Dish w/Grip Ring, Sterile, Volume 7-8mL Dish, Petri, Non-treated, 60mm x 15mm, polystyrene. Grip ring for easy handling. Growth area 21cm2. Working volume 7-8mL. Features: Sterile (gamma irradiated). Manufactured from medical-grade virgin polystyrene Ventilation ribs reduce condensation and allow air circulation Consistent flatness allows for even media distribution Flared lid skirt and squared corners for easy one-hand operation, especially with gloves