This Kimble-Chase 18 x 150mm lab tube is made of borosilicate glass. Borosilicate glass KIMAX-51 composition assures the best all-around chemical durability of commercial glasses now available for laboratory ware. Complies with ASTM Specification E438, Type I, Class B glass requirements. KIMAX-51 has excellent chemical resistance against sodium leaching - a factor common in soda lime glass products. This premium quality tube has a sturdy, uniform bottom and consistent length. Tubes are packed in convenient trays for ease of use on bench tops and in drawers. Trays are shrink-wrapped in plastic film with tubes remaining in constant alignment for protection against in-transit breakage and contamination. Designed from ASTM Specification E890. Size: 18 x 150mm. Material: Borosilicate Glass. Kimble-Chase #: 73500-18150.