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
· Designed from ASTM Specification E1043, Type III (9 mL) and Type III A (18 mL) requirements
· Manufactured from 33 expansion, low extractable borosilicate glass conforming to USP Type I and ASTM E438, Type I, Class A requirements