- RPM A-arms for the Typhon 4x4 3S BLX are everything you're looking for in a set of replacement A-arms. Adjustable, durable and lighter than stock. - Adjustability: With an added second shock mount to both front and rear A-arms to the outside of the stock shock mount, adding adjustability and improving trackability. Outer shock mount lowers the ride height, increasing stability on all surface types. A lower ride height also means faster corner speeds. - Durability: Molded from a trademarked blend of indestructible, engineering grade nylons, you can't get much tougher! With a redesigned shape of the A-arms while retaining stock suspension geometry to help improve survivability for those "oops" moments. - Lightweight: With stronger materials and improved designs, we're able to cut out unnecessary weight while still offering suspension components that are unparalleled in performance and durability. RPM Rear A-arms are more than 7 grams lighter per A-arm than their stock counterparts!