Step 1.2: Place for the helmet adapter
Is there enough space between the outer and inner shells?
Helmets without a sun visor have a gap between the outer shell and the inner shell into which you can clamp the helmet adapter with tabs. With some helmets, you must first open the gap slightly by pulling on the outer shell of the helmet with your hands.
Using a flat object, such as a plastic card or popsicle stick, check that the gap provides enough room for the tabs of the helmet adapter.