This hydraulic filter is used on early mid frame models. It was soon updated to the cartridge style filter, part number 1000382918. The serial number breaks are listed below.

SW16 before WNCS0501VPUM00543

SW17 before WNCS0502KPUM00549

SW20 before WNCS0504EPUM00526

SW21 before WNCS0503LPUM00549

ST28 before WNCS0505HPUM00552

ST31 before WNCS0506CPUM00618

When in doubt, flip the cab and check which hydraulic filter you need.

http://www.skyviewtractor.com/products/1000382918?utm_source=copyToPasteBoard&utm_medium=product-links&utm_content=web