This is a late victorian artifact & so uses hooks and eyelets to close as the zip hadn't been invented. While it does not include the ping pong ball thing, we will be auctioning a wooden engraved ball gag hand carved by a now extinct tribe of pygmies from the sahara desert. I understand that it was produced by commission to be compatable with an early victorian gimp mask which was in the possession of the explorer sir henry hardcock who discovered the tribe in 1886. I imagine an early victorian gimp mask should be much the same as design as it's descendants, and therefore would think it would be intercompatible? Perhaps some other experts could shed light from experience?