Patagonia boots are made of high-end Japanese superstretch neoprene for an amazing flexibility in the water. The exterior is made of smoothskin to deflect wind, and the interior is poly fleece lined for moisture wicking. Seams are sealed to keep cold water out. Split-toe construction and heel lock improve fit and performance on your board. Fine grip sole provides traction without sacrificing dexterity.
5mm boots are generally appropriate for 50 degrees and up
Patagonia does wetsuits differently. They stand behind every product with a lifetime warranty (does not cover wear and tear, of course.)