250ml Canted Neck Vented Sterile Culture FlaskGreiner Bio One products are manufactured in an aseptic, fully automated facility from the highest quality materials to provide maximum cell attachment and growth. The optical clarity of virgin material ensures cell culture containers are the best for microscope photography. TC surface treatment ensures improved cell adhesion attachment Free of DNase, RNase, human DNA Non pyrogenic, Non cytotoxic Optimal sterile gas exchange through a high airflow