Send your event to them and they will grade it and put it in a plastic slab.
The bigger the event - the bigger the slab. For example, send in a family BBQ event and get it returned in an autographed "Weber" slab with genuine grill marks. But -- send in a three-ring circus event and get it back, graded with blue cotton candy, in a giant autographed "Ringling Brothers" slab.
Fantastic!
[PS: New collectors -- This is all tongue-in-cheek stuff; feeble humor in a sometimes humorless world. NGC does only coins, medals --- and maybe the occasional petrified cat.]