Mayhem at Wicksteed - May 25, 26
Norbert Bruggen sells them. Thunder Tiger Neptune used them too, if you can find someone that sells spares.
It's here. Not sure what the switch configuration is. Ask Norbert.http://modelluboot.de/Zubehoer/Kleinteil.htmlAn alternative is have a go at making your own or just have a microswitch positioned to trigger when the bag is full.