Melting Point Tubes, Closed One End, 1.5mm-1.8mm O.D. x 0.20mm Wall, Vial of 100, 90mm Length. Similar to CG-1840, but closed at one end. Tube is manufactured from borosilicate glass and packaged 100 tubes per vial. The Code -02 has a smaller I.D. to conform to U.S.P XXI requirements.