this is a replacement drain cover for a slotted one that lets all the hair through. 3.25" bolt circle x 3 bolts. Flange is 0.15" thick. OD of flange in 3.62" "Funky" has a custom designed pattern with a flat bottom and raised top. My other one has round drain holes and reinforced bottom. measured the existing one, and then added my own drain hole pattern and thickened midsection for strength. Used visio to draw face pattern (uploaded) and then exported from visio to 123D via SVG format (attached). Extruded faces then faceted corners after subtracting a large concave face I created. exported as STL in to MB desktop. For the FUNKY one, I created a helical pattern overlaid on concentric circles to create the voids.