Product review (3 stars): Great filter but not 1/2 inch thick just over  a 1/4 (5/16) of an inch.  Solidly built though.
Beware this filter is NOT 1/2 thick but 5/16 just over a quarter of an inch thick.  It does not have a hook to hold one side as you insert the filter in its place.  The filter is built really sold and good.  I wish they were more accurate on the measurement of the size.