This 35mm/36mm low profile socket is used for the Ford oil filter cap, both fuel filter caps on the 6.4 PSD, and the primary fuel filter cap (the fuel filter located beneath the truck at the HFCM) on the 6.0 applications. The socket is from Lisle Tools and is a 3.8 drive. The socket is low profile, only 1 1/8 inches tall for the tight space at the HFCM filter. Do not use it with an impact. Shipping charges and options are based on your zip code and will show the amount in checkout.