Earl probably has the ones you roll to squeeze the air out.

I have some space bags, one that I'm storing yarn is has a leak in it, so it wont stay sucked, but at least my yarn is contained and not rolling around loose.

They work. I used to take orders for them back when I worked at a telemarketing company that took inbound orders for the crap you see on tv a lot. There were a few things that I liked when I worked there. Space bags was one of the few.