All Olympus Tips are precision manufactured to the industry's most rigorous quality control standards. All tips are made from virgin polypropylene and contain no recycled, reprocessed, or altered plastics that might introduce contamination or defects. Every lot of each product can be traced to the corresponding raw material and production date. All Olympus Tips are certified RNase, DNase, DNA, and Pyrogen-Free. In addition to the in-process control monitoring, all product lots are sampled after packaging and tested in our QC laboratory, thus resulting in a contaminant-free product of the highest quality. All Olympus tips are universal fit for research grade pipettors. These products may not be returned except due to quality defects, pipettor incompatibility, or receipt of an incorrect item.