C-IN2 Mens Underwear C-IN2 has recently become one of the world biggest contributors to stylish Mens Underwear, showcasing xome of the hottest and sexiest styles seen in a long time. Whether it’s style, comfort or design, the CIN2 Mens Underwear collections, Boxers, Sling Underwear and C-IN2 Briefs have it all. Not to be outdone the swimwear offers the same stylish and daring designs for playtime at the beach. C-IN2 swimwear is created by the same design team behind the Mens Underwear range.