They are just a pair of board shorts with his sponsors and logo patch on. I don't think they are a particular brand. If anything it looks like they are BTT brand shorts in an exclusive green shade for Arona. You can find red ones here. http://www.brazilianfightwear.com/s...52527290&Store_id=117&page_id=23&Item_ID=1496
Arona patch to buy here if you care enough: http://www.brazilianfightwear.com/s...14571093&Store_id=117&page_id=23&Item_ID=1211