The Accufab 125mm is made from 6061-T6 billet aluminum and polished to an eye-catching finish, plus our quality is second to none! Only the best components are used for unparalleled reliability and performance. For example, this unit features a stainless steel split shaft design with four ARP screws to hold everything securely together. Also, new to this throttle body is the linkage with two threaded holes to utilize a 10/24 threaded ball stud or your choice of other products with this thread size. You can use either hole, depending on your application, to open the throttle blade correctly. Manufactured and assembled in the USA. This throttle body may be used with an intake manifold featuring a 4.5" bolt center to bolt center square bolt pattern. In addition, these units have a built-in V-Band ferrule machined on to the leading edge. The ferrules are designed for a 5-inch intake pipe leading up to the throttle body. Also, an o-ring groove is machined into the rear of the throttle body, guaranteeing a leak-free seal to the intake manifold.