The foundation of the Immersion Research Royale Spray Skirt is the proprietary “fin” shaped rand designed to make maximum contact with the rim and resisting implosion to the very end. In addition to the rand shape, there are also two sticky rubber patches under the deck on the sides to provide additional implosion resistance. Also, the deck neoprene has been extended 2″ past the rand to offer unsurpassed dryness on a variety of rim shapes. In the high wear areas, there is the most expensive and strongest 4-way stretch kevlar that can be found (the red material around the front). All of the seams are glued, taped and stitched.