I received these covers on Tuesday May 3 and they fit perfectly.  That evening we covered the loungers, with the Sunbrella cushion underneath, and snapped then tight on.  About an hour later we were hit with torrential thunderstorms that went all night and dumped 3.5 inches of rain.  When I went out the next morning to see if the covers really were 100% waterproof I was thrilled to find perfectly dry cushions!!  They really are waterproof.  No more lugging the cushions indoors at night.