Passive Ball Stop
This miracle piece of metal will keep your machine's pinballs in the trough while your playfield is in the upright postion. Gravity slides the gate into place keeping your pinballs snuggly in the ball trough. When you lower your playfield the gate swings back open.
Originally designed for the Pinball 2000 series of machines, this device can be retrofitted into any Williams/Bally game after Twilight Zone that has a star post behind the ball trough in the shooter lane (you will have to take your game's apron off to see the star post clearly). See secondary photos above (click on them to enlarge).
Installation takes less than 5 minutes and requires no permanent alterations to your machine (instruction sheet included).