3" Aluminum single shaft for all the Subaru platforms. These shafts are in some of the fastest Subaru's around the world including Easy Streets WRX and Big Valleys STI. the shafts do have some clearance issues so the floor will need to recontoured a little (some floor braces flattened along with the floor you must have ?" clearance all the way around the shaft in every area) these shafts are designed for street use but may also be used for racing, so we need to advise you the shaft has a 600WHP max and a critical speed of 150mph. These shafts have had more than both put into them but these are the recommended limits. This shaft is less than half the weight of the factory 2 piece and by eliminating the hanger will remove the lag the factory shaft has when the hanger moves up and down.