Thick uniform walls throughout and extra wall thickness built into the evenly tooled top rim
· Uniformity of construction allows for use on hot plates
· All sizes have a durable matte finish marking area and a white graduated scale
· Design meets ASTM Specification E960, Type II requirements
· Manufactured from 33 expansion, low extractable borosilicate glass conforming to USP Type I and ASTM E438, Type I, Class A requirements