A supporter of the Belgian national soccer team poses with a "diabolica" trumpet at Mons soccer stadium May 16, 2014. Ear-splitting vuvuzelas were an ever-present backdrop to the 2010 World Cup finals in South Africa. Four years on, two Belgian entrepreneurs hope to fill stadiums in Brazil with the high-pitched noise from plastic trumpets dubbed "diabolica". REUTERS/Francois Lenoir (BELGIUM - Tags: ENTERTAINMENT SPORT SOCCER WORLD CUP BUSINESS)