New Top Quality BSA Gas Tank Hinged Winged Alloy Filler Cap. If your looking for an Accurate Reproduction Gas cap then this is your ticket! Even comes with a nice polished finish. Gas Cap features a “Wing” and fits 2 1/2″ Filler Necks. Fits BSA Unit Twins (Lightning, Thunderbolt, Rocket, Etc) from 1962-1970 that where equipped with the 4-Gallon Petrol Tank & 2-Gallon Tank that can accept the Hinged Gas Cap. Also Suitable for Royal Enfield, Triumph & other BSA models that can accept a 2 1/2″ Hinged Gas Cap. Please refer to your parts catalog for proper fitment.*****Please note that this Gas Cap will only fit tanks that can accept a Hinged 2 1/2″ Gas Cap! Check your parts book and gas tanks!*****Made in TaiwanO.E.M Part number is 68-8083, 03-3001 or 48705A