24PK Test Tubes, 30ml - Borosilicate 3.3 Glass - 1.2mm Thick Walls, Beaded Rim - Superior Heat & Chemical Durability - 5.9" Tall, 0.8" Diameter - Eisco Labs

Made of high quality Borosilicate 3.3 Glass Eisco Labs Borosilicate glass heat tolerances: Strain Point -515°C | Annealing Point 565°C | Softening Point 820°C Autoclavable, with superior chemical durability Low temperature gradient- can withstand direct flame, high temperatures & thermal shocks