Quality and performance cannot be evaluated easily. Some users select oil filters by price alone, but oil filters have crucial effects on engine performance and integrity. Cheapest is not always the best. Vesrah spin-on and regular replacement cartridge type filters are manufactured by OE factories to meet or to exceed the OEM motorcycle specification and are built from a selection of high quality materials. They meet or exceed all OE performance requirements. O rings may be included, but if it is a crucial requirement, please call our sales office to check. They will be happy to confirm if they are included or not in your specific product Filter Materials: The filter material in Vesrah filters is a composite of paper pulp, along with organic fibres and resins, which is processed to produce an extra thickness and density and provide high filtration. Design: Vesrah filter materials are fluted to their maximum and at least to the OE required numbers. The higher the number of flutes, the higher the filtration efficiency. Although this process incurs the most cost, this has the most crucial impact on filter quality. Outer casing: Vesrah spin-on filters are designed to match or exceed OE thickness standards, so that Vesrah filters will withstand oil pressure and vibration without inhibiting their primary operation.