These clean, sterile pipettes are calibrated to deliver with blowout and are packaged ready-to-use. They feature a uniform drawn or molded tip and molded, cotton-plugged top ends. Sharp, black ascending and descending graduations simplify fluid measuring and dispensing. Individually-wrapped pipettes come in paper/plastic packaging and are color-coded for easy size identification. Do not pipette by mouth. Use of a mechanical pipetting device is suggested.