The funnel is a a WHITE CIRCULAR OBJECT about 10 inches in diameter and 3 inches high with a hole in the middle.
Euclid discovers that stacking five funnels triggers a process in which the five collapse, and then burst:
Suddenly he notices the stack of 5 Funnels COLLAPSING. One after another, they each drop, erasing the gaps between them. When they are completely compact the texture of the Funnels changes slightly for a fraction of a second, like a THOUSAND TINY HOLES silently flitting open and closed. then the Stack goes neutral and the GAPS between the Funnels return.
The boys also discover that once they are connected, they cannot easily be detached:
He reaches out to carefully lift the top Funnel, but when he does the entire Stack comes with it, connected somehow.
We learn later that aged funnels can be detached with force, and new funnels can be attached to the stack.
The boys experiment with Funnel Stacking until they create a stack with 20 funnels. It is now that they find that the funnels generate enough energy to launch into the air:
The last Funnel contracts and in an instant the entire Stack SLAMS against the desk with a DEAFENING BANG and disappears. Papers and everything on the desk are sent into the air. The kids all recoil. When they compose themselves they look up to the ceiling. CUT TO: The Stack has embedded itself halfway through the exposed plywood of the first floor ceiling. Euclid and Carter are cutting into the wood with a HAND SAW to free it.
During this scene, Carter discovers that, by holding the controller away from the funnel stack, he can reverse the launching process.
Later on in the screenplay, the boys decide to write their names on the funnels to indicate ownership. It's not clear how funnel ownership is established, but you'd presume it relates to who was handling the maker or the flat-disc, when it was ejected.
Controlling the Funnel Stacks
Initially, the Funnels stacks appear to launch when the boys approach the stack with their controllers.
Later in the story, we learn that the funnel stacks respond to their owner's voice commands that can be pre-recorded onto cassettes. The commands are listed as:
GEORGE (ON TAPE) Ready, set, jump up. ALBERT (ON TAPE) One, two, three. JAVIER (ON TAPE) Mark, get set, go.
Javier discovers that you can peel off layers from the funnel. By using an overhead projector, they magnify the material to reveal:
It contains a series of ABSTRACT SHAPES connected by a network of tunnels.
It appears that after an unspecified amount of time, the funnel ages. The aged funnels are described as follows:
The bottom Funnel shows some cracking and is brown and translucent.
Vaughn discovers that, using some force (and a pair of pliers), he is able to remove aged funnels and replace them with new ones. The aged funnels are used to create petals.
Decayed Funnel Usage
Later in the script, a Chorus is seen turning a decayed funnel into power, which is then used to feed the circle frond, which was originally held inside the maker.