On most camcorders the adapter ring (which is also your filter size) is written on the front of your camcorders existing lens.
Look for a circle with a line through it (Ø)...the number right beside that circle is the camcorders adapter ring/filter size.
Example:
f=3.9~62.4mm f1.6 Ø 37mm (Adapter ring size.
Click Here for Visual
Questions? Call technical support directly at 1.800.601.7511