1 – Hold firmly the main metallic part and push the pin until the end of it (Picture A);
2 – Use the other hand to inflate repeatedly squashing the black rubber part of the inflator (Picture B);
3 – Pull out the inflator using the metallic part without pulling the clack rubber part of the inflator (Picture C);
N.B. – During the inflating process the metallic part must be always held in your hand pushing directly to the gym ball.
Recommended for precision inflations of professional gym balls.