This is a Dragon Quest Celestial Shield and Helmet action figure accessory set from Square Enix, dated 2009.  This is from their Legend Items Gallery line, which appears to be a Japanese Import.
   
The shield is approximately 2 inches high and 2 inches wide, and the helmet is a total of 1 1/2 inches long from the front to the wing tips, and looks like it should fit on a 3/4 inch wide action figure head.  Please be aware that these measurements are only very close approximations, as they were taken through the packaging without the pieces being removed.
   
As shown, this set is still new and sealed in its plastic tray and clear plastic wrapper.  I have no idea if the entire package originally came on a card or in a box or some other outer packaging.  The bag has a rip in it near the top where a price sticker had been peeled off.  See pictures for details.