The Excursion Funnel is a testing element from Portal 2. It is a beam that either pushes objects away from its emitter, or pulls objects towards it. It was added in Mari0: SE.
In Mari0, they act almost exactly like in Portal 2. They take up two tiles.
In SE beta 9, a reversed funnel will cause the game to crash. This can easily be remedied by going into funnel.lua and, at line 220, changing
"endimg = excursionfunnelendimg2"
"endimg = excursionfunnelend2img"
- At speed 50, the graphic stays perfectly still.