Sealed-to-contain 9mL skim milk pipets are designed to comply with the Pennsylvania modified Babcock method, as referenced in APHA 15.8, for testing skim milk, lowfat milk, buttermilk or whey. Scale is permanent brown stain. Specially designed rubber washer is supplied with each pipet and is used to support the pipet in the neck of the test bottle. Marked with "Sealed 3" for use in states requiring this marking. Manufactured from 33 expansion, low extractable borosilicate glass conforming to USP Type I and ASTM E438, Type 1I, Class A requirements.