Fisherbrand 1000ul SureFit Ergo-F Pipet Tips Natural Fisher Scientific Designed specifically for use with Fisherbrand pipettes Available in three capacities, with or without aerosol barrier Unique wall design provides an extra-strong seal specific to Fisherbrand pipettes Require minimal ejection force Certified by an independent laboratory â?? Nonsterile: RNase, DNase, DNA, and Pyrogen Free; Sterile: RNase, DNase, DNA, Bioburden, PCR Inhibitor, and Pyrogen Free