Jacketed Flasks are essential for any research lab, featuring an additional layer -- usually glass -- which encases the main flask. This separation creates an insulated space, enabling users to keep the interior at a steady temperature during experiments and processes that require precise temperature regulation, such as organic synthesis, distillation, and crystal growth. Jacketed Flasks: Round Bottom Jacketed Flasks for distillation, Three Neck B29/32, Heavy Wall Flask, two hose connection for hot or cold liquid circulation. NOTE: EUD REQUIRE FOR THIS PRODUCT PURCHASE Item Code Inner Flask Diameter Outer Flask Diameter Height Capacity (ml)/ Wall Thickness 10.00.Jak1000 135mm 160mm 250mm approx 1000 / 4-5mm 10.00.Jak2000 168mm 215mm 350mm approx 2000 /4-5mm