The Suunto EON Steel Bungee Adaptor allows you to convert the standard elastomer strap to bungee cord. Many divers prefer bungee cord over a traditional strap as it is easier to slide the computer on and off your arm, it also has the advantage of being depth compensating when your suit compresses. Bungee cord is also easily replaceable in the field in areas where a proper strap may be hard to source.