I designed this adapter to be able to inflate the Gym Ball Fitness using a common cheap air duster. The nozzle is conical and fits into any hole between 5 and 10 mm in diameter, while the hole to fix it on the blower is 16 mm.

The printing profile is stronger than the standard one to avoid unpleasant breakages. Be wary of any other Spam portals, especially if they promise to save a handful of minutes at the expense of quality and resistance!