Graduated Borosilicate Test Tubes - 18 x 150 mm, Pack of 50The 18 x 150 mm Graduated Borosilicate Test Tubes are built for high performance in educational and laboratory settings. Crafted from strong borosilicate 3. 3 glass, these test tubes are autoclavable and can withstand high temperatures and chemical exposure. Their clear graduation marks every 0. 5 ml and 25 ml capacity make them ideal for experiments requiring precise measurement and repeated heating. They are also designed with standard round bottoms