This 35mm/36mm low profile socket is used for the 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 HCFM) on the 6.0 applications. The fuel filter located beside the oil filter on the 6.0 can be removed with an 1/2 drive extension and racket. The socket is from Lisle Tools and is 3.8 drive. The socket is low profile, only 1 1/8 inch tall for the tight space at the HCFM filter. Do not use with an impact. Shipping charges and options are based on your zip code and will show the amount in checkout.