Maxpower 7127 Idler Pulley Replaces Murray 420613, 91178 Fits 25 Inch, 30 Inch, 36 Inch, and 46 Inch rear engine riders model 7-35500, 7-30502, 7-25501 3 Inch OD, 1/2 Inch ID, 11/16 Inch Height Composite: glass filled nylon