This blue medium grade foam pad helps remove debris from your aquarium. This foam has been precision cut in the UK and will fit the Discount Leisure external aquarium filter model HW-303 and HW-403 and its UV version HW-403B
Sun Sun are the manufacturer of this filter and you will find that this same filter is often re-branded and re-named, therefore this foam will fit many other brands of filter.
Part Number of external filters this foam fits