The flag grabber level features a mechanical one-way trap door (bottom right) that closes when a flag enters the cavity. To accomplish flag grabbing, the one-way mechanical valve has a trap door attached to a swivel shaft, a mechanical stop to hold a trap door in place, and an elastic band to allow for repositioning when a flag is fully inserted in the cavity. The succession of a flag entering the flag cavity, extending the trap door, and the trap door snapping back into place is shown below.
