8mm or 10mm oval universal base plate with handles and spacers to adjust the height,comes with or without collet and 30 degree cnc bit.
Hole in centre is 38mm but can be cut a different size.Just put your router on the base and mark and drill the fixing holes.Pics are with the base on an A4 sheet to give you an idea of size. A4 or other size pieces of 8mm or 10 mm. available.