This is a brand new set of 2 phenolic carburetor mounting spacer block used to reduce heat transfer to the carb body.
Amal part # ABF815
Triumph, BSA or Norton part # 70-2968, 70-4918, E2968, E4918, 06-3458, 06-2700, 71-2593
Inside Diameter: 32mm
Stud Mounting center to center: 2″