This is an authentic filter for Leveluk series machines that uses HG-N model filters. SD 501, SD 501 Platinum, JRIV, JRII and R. This is the filter that have a double notch on the middle port. Do not be tempted buying an imitation as it is much as well better to just stay with the expired one than buying a cheap imitation that does not remove the Chlorine from the water that they are supposedly designed to do so in the first place.
eBay