Round body 3-1/4 inch shell diameter, A= 2-3/4 inch inlet length, B= 2 inch inlet inside diameter, C= 16-1/2 inch shell length, D= 12-1/2 inch outlet length, E= 2 inch outlet outside diameter, F= 32 inches overall length. For tractor models (30, 20, 31, 32, 40B, 50 all with gas or diesel engine), (230, 240, 250 all with Perkins Gas or Diesel Engine), (290 with Perkins Gas or Diesel Engine also must use 898534M1 OEM number tailpipe).