THIS IS A SINGLE ENGINE PUSHROD INLET OR EXHAUST TO SUIT UNIT 500 TRIUMPH TWINS PART NUMBER E4008, 70-4008. SUIT ALL 5TA , T100 AND TR5T MODELS FROM 1958 TO 1974 IF YOU HAVE ANY QUESTIONS ABOUT THESE ITEMS THEN PLEASE GIVE US A RING ON 01371 876027. PLEASE NOTE WE OFFER COMBINED POSTAGE COSTS ON MULTIPLE PURCHASES BUT PLEASE WAIT FOR US TO SEND YOU THE TOTAL COST BEFORE PAYING