Gerard Martowlis from the US is one of the first to engineer his own rocketbelt after Tyler and the RB2000. It took him several years to build, test and fly his own belt. At first with a ball valve, later on with the "KWL" valve. He attended the 2006 and 2007 rocketbelt conventions with his rocketbelt. In 2007 he made a static test in front of thousands at the Thunder over Niagara Airshow. I visited him back in 2013 at his hometown. Great time!