though you could really use either style cap you like

Big Twin (Panhead

• Complete Replacement Kit: Includes the isolator mount (OEM 16287-04)

75" from the plate to the top of the shift knob threads (5/8" of threads included)

Origin: Made in Ohio

Sporty 2-Up Seat - Black Diamond - 2004-2021 Harley-Davidson Sportsters Subcategory_Petcocks though you could really useThe Diamond Sully's 2 up seat fits 2004 2021 Sportsters (EXCEPT models with 3 gallon tanks and 2021 SPORTSTER S RH1250S), and bolts in place using the stock fender mount nut, bolt, and hole. These seats are USA made start to finish in Centerville, Indiana at Sully's Customs. See Additional Information for fitment. NOTE: Will not fit 2021 Sportster S RH1250S NOTE: Will not fit models with 3 gallon tanks NOTE: 2007 2009 models have the ECM located under