The MA-1 TT is similar to the MA-1 in terms of appearance (it also comes with the iconic red flight tag and pencil box on the left sleeve) but it actually features a slimmer cut to promote a closer fit to your body. Since it’s a summer jacket, it was conceived to allow space for a shirt but not for these Norwegian sweaters many grandmas love to give away on Christmas Eve. As a result, the MA-1 TT is a great companion for mild summer nights. Alpha Industries. Ytterstoff: 100% nylon. For: 100% nylon. Passform: Slim-fit.