GP Plus R V4 Rideknit Leather Jackets Alpinestars GP Plus R v4 RIDEKNIT Leather Jacket is optimized for superior freedom of movement and rider comfort, and features extensive race-derived features and materials including a dedicated ‘Sport' fit with pre-curved arms for maximum riding performance, and race-proven protection on shoulders and elbows Alpinestars composite stretch technology, A-CS Plus, stretch panels on the torso for exceptional breathability, comfort, and freedom of movement, as well as delivering a lighter weight and a lower profile than a traditional leather accordion panel (the A-CS Plus panels are about nine percent lighter than leather panels). Another key advantage of using A-CS Plus is its superior stretch performance; A-CS Plus has about 30% elongation, and offers an increase in tear resistance of 300% compared to HRSF (Hyper Resistant Stretch Fiber), and an increase in cut resistance by 600% versus leather 1.3 mm ‘Race' grade leather construction for optimum blend of abrasion resistance and comfort RIDEKNIT engineered inner arms; RIDEKNIT combines high abrasion and tear resistance with high flexibility, comfort and mechanical stretch while still delivering superior comfort and high levels of breathability Extensive technical stretch panels under the arms, on the inner arms, and around the neck for an optimized fit. Dual density DFS shoulders for superior friction control GP Lite elbow armor for impact protection in a key area Nucleon Flex Plus shoulder armor for superior impact protection Tech-Air 5 and Tech-Air 3 ready