This is a 3/4" drive 20mm 12 point lower idler gear socket.
This is made for use on : Pre 2004 530E, Pre 2004 DT466E, 2004 - 2007 570, 2004 - 2007 DT 466, 2007 MaxxForce 10, 2007 MaxxForce 9, 2007 MaxxForce DT, 2010 MaxxForce 10, 2010 MaxxForce 9, 2010 MaxxForce DT, 2013 N10 w/SCR, 2013 N9 w/SCR, AC / UC & HT / TC Commercial Bus, AE, BE, CE & Integrated Bus, CityStar / CF Series , CXT, MXT , DuraStar , EStar , LoadStar , RE Integrated Bus , TerraStar , WorkHorse , Base Engine , 12 Engine System. This is a replacement to ZTSE-4383