RASH GUARD. MMA Rash Guard also called with vest rash or rashie is an athletic shirt made of spandex and nylon or polyester. This shirt can be worn alone or under a wetsuit. But over time, Rush Guard is also much-loved by other sports such as mix martial art, cycling, and much more. In custom.sg we provide 2 kinds of material for MMA Rash Guard. Premium Jiu Jitsu Gis; Mens No Gi Armor; Womens No Gi Armor; Fight Shorts & Spats; Rash Guards; Rip-Stop Pants; Kids. Kids Gis; Kids Rash Guards; Kids Shorts; Premium Jiu Jitsu Gis; No Gi Armors; Ranked Rash Guards; Fight Shorts & Spats; Rip-Stop Pants; Accessories. Gym Bags; T Shirts; Hoodies; Thick BJJ Belts; Custom Products; Uncategorized.