It's a manual vacuum pump... my mother had one of these 20+ years ago before all the home sealing machines were available. I don't find it necessary. I keep my fondant in heavy plastic and store it in a sealed plastic bucket and it keeps for ages.
I use my FoodSaver vacuum system. There are several kinds of containers that you can use with this system. I have used it for royal icing, fondant, gumpaste and it seems to keep forever.
Here's a link to their product page:
Hope that helps
I've never used one either. I just coat it in crisco, saran wrap it, ziplock bag it, and then stuff it in an old Satin Ice bucket.