Adjustability
Fast Metal's Speed Demon and Pioneer models of aluminum frames can be adjusted slightly for tighter or looser fit. Follow this simple technique below:
To make larger:
Open the temples as if you are about to put the frames on. Hold the frame by its edges, on the frame side of the hinges with the nose facing you and resting on your chest. Slowly pull the frame outward symmetrically by no more than 1 inch, then allow it to return to its normal shape. Do this 5 or 6 times with slight force and then try the sunglasses on. If it is still too tight, repeat until you accomplish the desired fit.
To make smaller:
Open the temples as if you are about to put the frames on. Hold the frame by its edges, on the frame side of the hinges with the nose facing you and resting on your chest. Apply pressure symmetrically inward and compress the bend to be smaller by no more than 1 inch, then release and allow the frame to return to its original shape. Press inward 5 or 6 times and try on to fit. Repeat until desired fit is achieved.
View Speed Demon and Pioneer Owners Manual