Phenolic Amal Carburetor Insulator 28mm Triumph Norton BSA thin Norton Drive Ducati's original part number for

Ducati's original part number for the rust-prone black versions was 0440-12-013

Shouldn't show or affect use once installed

A beautiful rendition of the cast aluminum cap

Triumph's part number should be 82-4585 or F4585

earlier rectangular master cylinders use a different setup

Phenolic Amal Carburetor Insulator 28mm Triumph Norton BSA thin Norton Drive Ducati's original part number forTriumph BSA part number 70 7819. (Any earlier part numbers for a 28mm insulator supersede) Typically used between carb and manifold for 250 single, 500 twin and some single carb 650. American made, GUARANTEED to fit. Thickness 1 16". Thicker versions available in another listing.