5 piece Erlenmeyer Flask set made of high quality, heavy duty, borosilicate 3.3 glass. Includes five, narrow neck flasks with 50ml, 150ml, 250ml, 500ml & 1000ml capacities. Flasks feature white, printed graduations, and beaded rims. Uniform, thick walls provide excellent strength against breakage. Set is packaged in a custom fit, thick foam casing, for safe storage and worry free transport.Measurements:[ 50ml ] 3.3 tall, 2 wide base. Neck, 18mm inner diameter, 22mm outer diameter.[ 150ml ] 4.6 tall, 2.9 wide base. Neck, 23mm inner diameter, 28mm outer diameter.[ 250ml ] 5.7 tall, 3.3 wide base. Neck, 29mm inner diameter, 34mm outer diameter. [ 500ml ] 7 tall, 4.25 wide base. Neck, 29mm inner diameter, 34mm outer diameter.[ 1000ml ] 9 tall, 5.25 wide base. Neck, 36mm inner diameter, 42mm outer diameter. Microwavable and autoclavable, with superior chemical durability. Low temperature gradient- can withstand high temperatures & thermal shocks. Eisco Labs Borosilicate glass has the following heat tolerances: Strain Point 515°C | Annealing Point 565°C | Softening Point 820°C.Eisco Labs proudly manufactures its own products using state-of-the-art equipment, and following the highest standards of quality control.Each product is carefully designed by a team of laboratory professionals and experienced engineers with quality and durability in mind. They are manufactured with only the highest grade, raw materials and according to international quality standards to ensure that they can withstand use in even the toughest laboratory environments.