The sizes of the GUPPYFRIEND filters are based on the DIN standards for street and yard drains, which are commonly used at sports facilities.However, the two GUPPYFRIEND drain filter variants also fit when there are deviations from the standard. With the GUPPYFRIEND filter, structural deviations from the norm are compensated for by using seals.The next larger filter ring must be selected and then cut to size for intermediate sizes or custom-made drains and drain boxes accordingly.We currently offer a GUPPYFRIEND filter that can be adapted with seals and two GUPPYFRIEND filter versions, one for small and one for large drains. However, individual designs are possible, so please get in touch.