Manufacture and patents

In June 2004, Crocs purchased Foam Creations and their manufacturing operations to secure exclusive rights to the proprietary foam resin "croslite", which is made using ethylene vinyl acetate.[5][6] The foam forms itself to a wearer's feet and offers purported medical benefits, according to a number of podiatrists.[7][8]
Crocs holds four patents covering various utility aspects of its footwear, U.S. Patent No. 6993858 B2 issued February 7, 2006, and U.S. Patent Nos. D517788,, D517789 and D517790 issued on March 28, 2006. The Company also announced that it has filed complaints with the U.S. International Trade Commission (ITC) and the U.S. Federal District Court against 11 companies that manufacture, import or distribute products called Crock-offs that Crocs believes infringe its patents.[9]
As of December 31, 2007, they have applied to register Crocs and the Crocs logo as trademarks in over 40 jurisdictions around the world, including the U.S., but such applications have not been approved and are currently pending. In addition, they have recently extended the scope of their trademark registrations and applications for both the Crocs mark and logo to cover non-footwear products such as sunglasses, goggles, knee pads, watches, luggage, and some of their internet sales activities.[10]