It is also fully optimized for use with or without Tech-Air® 5, Alpinestars world leading electronic airbag safety system. Alpinestars SMX Waterproof Jacket - Black/Dark Grey/Bright Red - 1993. With a main chassis constructed with 600D polyfabric and stretch softshell for the optimal blend of durability, light weight and comfort, this jacket features subtly incorporated class-leading Nucleon Flex Plus armour for proven impact protection.