Vacuum Mixing Bowls are a hand mixing unit with no excess spatulation. These bowls are made of thick, hard rubber and will not collapse. It’s quick to disconnect from the vacucm inlet and the bowls includes a quick disconnect and tubing. Extra O-rings on the disconnect are for better maintenance of vacuum. There are also three O-rings on the spatulator shaft to prevent vacuum loss and investment creep along the shaft. The bowls are easily cleaned and maintained.