Big Filter BFS-EAA1 is compatible with WIX P/N 51685 in form, fit and function.Technical Specifications: Filter Type: Pressure Line Product Media: Glass Height: 4.56 in OD Top: 3.09 in ID Top: 1.72 in OD Bottom: 3.09 in Beta Ratio: 200/5.4 Micron Rating: 5 Fluid Type: HH / HL / HM / HVYou know you have received a quality Big Filter hydraulic filter when you our logo on the filter box with our brand name and part number.Our filters are built with the highest quality and reliability in mind so you know your equipment is safe and can keep running smoothly.Big Filter hydraulic filters can be used in a variety of industries including but not limited to: power generation, defense, oil/gas, marine and other motor sports, shipping and transportation, railroad, mining, pulp and paper, steel making and manufacturing, entertainment and various other industries.All of our elements are manufactured according to ISO specifications, including: ISO 16889, Clean DP (low and high visc.) - ISO 3968, Fluid compatibility - ISO 2943, Flow fatigue resistance - ISO 3724, Dirt capacity - ISO 16889, Collapse pressure - ISO 2941All items marked "Replacement" or "Interchange" are not affiliated with the original manufacture where names and part numbers are for cross reference only. All trademarks are trademarks of their respective owners. Reference is made to the OEM solely to identify the compatibility of Big Filter Inc. filter with the OEM filter.Images may be general representations of products and may vary from image. All items are sold by 1 unit unless a pack size is listed in the title description.