Birkenstock Sandals MADRID BIG BUCKLE Insignia Blue leather regular fit. Birkenstock Sandals MADRID BIG BUCKLE Hex Premium Insignia Blue leather regular. Please look at the Birkenstock’s sizing chart posted in the listing before buying and use it to figure out your actual size. This is a very rare item, highly sought and hard to find specially in this color and fit (regular). Excellent conditions. Brand new with tag