TUBULAR VOKES AIR FILTER D. 7226 FIT ARIEL BSA WD M20 MODELS – UK SUPPLIED. This high quality Air Filter is made in our dedicated production facility and quality checked prior to dispatch from our UK warehouse in Birmingham. ARIEL BSA WD M20 MODELS. GREAT PRODUCT, GREAT PRICE AND GREAT SERVICE. We are the premier supplier of vintage and classic motorcycle parts in the UK and Europe. Our high quality range of classic motorcycle spares and accessories covers all great British makes – AJS, BSA, MATCHLESS, NORTON, TRIUMPH, ROYAL ENFIELD, VELOCETTE, VINCENT. We also stock spares and accessories for international makes – BMW, DUCATI, HARLEY DAVIDSON, HONDA, INDIAN, MOTO GUZZI, NSU, ZUNDAPP.