Designed as a complete charging system with a built-in regulator

Specific Fitment: Designed to be a perfect fit over any 1-3/4" outside diameter exhaust pipes for a simple installation

This is the proper way to drift the block out without damaging it

and required hardware and o-rings

Black natural rubber sandwiched between two threaded 5-16"-18 studs

30mm Carb Phenolic Spacer for Triumph BSA Norton #70-7821 Motorcycle Specific_Harley-Davidson Sportster Designed as a complete chargingThese are phenolic spacer insulator blocks, basically hard 1 8" thick spacers for 30mm (928 930 932) Amal carburetors as run on Triumph, BSA and Norton motorcycles. Help keep the heat and vibration from getting to your carbs and gas. Sold individually. OEM #70 7821.