Split 6A - Split Optic Mold for Glassblowing. The Split 6A is 4" tall with a 2" opening at the top that tapers to a 1-1/2" opening at the bottom. This split air trap mold is great for putting bubbles in your work or texturing the outside of a piece. It comes equipped with a base plate and handle or kick lever. The mold is made of cast aluminum.