50 mL Racked Centrifuge Tubes have a glass-like clarity, allowing easy viewing of the sample, printed graduation markings, and frosted writing area make for easy identification and measuring. Material is made from polypropylene and is sterile. Red polyethylene (HDPE) caps feature leak proof design. RNase/DNase free to help ensure optimal reliability and performance. Additional details on MLS-CTPR-50P: Non-pyrogenic. Non-cytotoxic. Conical Bottom. Max Force 14,000G. Manufactured under ISO 13485:2012 and ISO 9001:2008 quality management system. 25/rack, 12 racks/case.