Simax Flat-Bottom Spherical/Boiling Flask, 4000ml, Diameters: 1 - 207mm, 2 - 50mm x 300(H)mm, Narrow Neck w/Rim, Boro Glass, Clear, Each

These flasks have long necks with tooled mouths and take a matching size rubber stopper. Wall thicknesses are carefully controlled to provide the proper balance between thermal expansion and mechanical strength for greater shock resistance. Their excellent chemical durability results in contamination-free results and long life under the toughest lab conditions.