This Corning microplate lid is made of rigid polystyrene. Lid does not have a corner notch on the A1 corner and does not need to be oriented in any particular direction to be placed on Corning plates. It has a shorter skirt than standard lids. Sterilized by gamma radiation. Lid does not fit Corning 2µL 1536-well microplates. Sterile. Material: Polystyrene. Plate Format: Lid. Surface Treatment: Not Treated. Corning #: 3098.