45 TOOTH CHAIN DRIVE SPROCKET MODEL 25A-5A2. TAPERED TRIPLE KEYWAY HUB SPLINE @ 4.25" DIA ONE SIDE AND 3.75" DIA. ON THE OPPOSITE SIDE. 22.25" O.D. TO SPROCKET TIPS. SPROCKET HAS FOUR 3.5" DIAMETERS HOLES. SPROCKET WEB THICKNESS IS 7/8" WITH A HUB WEB THICKNESS THROUGH SPROCKET OF 3". SPROCKET APPEARS TO BE UNUSED.