This is 4 parts (2 parts of the screw plate) needed to make a fully functioning reaction vessel for chemistry experiments. With some welding needed if done in high temperatures or a vacuum, this reaction vessel can be put in a furnace and sealed for high temperature distillation. Rather than a one time use sealable distillation vessel, or one that is extremely hard to clean, you can simply undo the screws to open this one after the distillation has taken place. I recommend using a gasket (Something like a mica gasket) in between the two screw plates to have an effective vacuum. Attached is a picture showing where to weld the pieces together. The long tube you can see attached to the top is simply a 26mm diameter stainless steel tube you can easily find for $15. The purpose of it is to let the reactants cool before going into your desired chamber (ampule, vile, etc.) This is especially necessary if you are dealing with something such as a caesium distillation involving lithium, going into a glass distillation apparatus. You wouldn't want that lithium to still be hot. (; Let me know if you have any questions or would like more information on how it works.