Dexter 3 1/2" Oil Cap, O-Ring, and Plug Kit (1 Pair) 3 1/2" Dexter Oil Cap, O-Ring, and Plug Kit Features and Specifications: Fits Dexter 9K, 10GD, and #13G (after July 2009) Outer diameter of threads: 3 1/2" 12 Thread Includes: (2) 21-88 - Thread in oil caps, 3 1/2"-12 (Dexter 021-088-00) (2) Rubber plugs (Dexter 046-032-00) (2) O-rings (Dexter 010-163-00) Manufacturer / Brand: Dexter Axle Manufacturer Product #: K71-704-00