what's you vacuum (or similar other technology)? how often do you use it? is it a good one?

also how often do you play with vacuums? I was in the retreat last night and someone was demonstrating how she teacheded some kids what happens if you go in space or under lots of was by putting a marshmallow in a syringe.and then i was allowed to play with her marshmallows and syringe and i maded a vacumm and then i maded a really small marshmallow by crushing it with air.