Chrome Pancake Air Filter for 1-1/2 inch  HS4 1.5 SU Carburetors - PF102a

The pancake Filter has a foam ring sandwiched between two expanded metal rings... one outside that you can see and one internal that holds the shape of the sponge. 

Chrome pancake air filter for 1.5" SU. 5.5" diameter, offset mounting

This filter is designed for Mini models with single or twin SU HS4 1.5 inch carburetors and has an offset mounting hole

Sold as single filter, you would need two if fitting to twin carbs.

(Note the peel back blue protective screen to save against scratching.)

Dimensions:  140mm x 25mm

To Suit Vehicles
Classic Mini

Alternate parts : 

SGPF102a