The description says "Low output ripple makes it performs more perfect."
I've ordered from Satistronics in the past and they have been quite good. I even have two of the aforementioned DC-DC switching power supplies, if you buy directly from Satistronics, you pay about $3 less each.
Looks like they added an addition LC filter on the output of this board, not suggested in the datasheet, for the better ripple spec they are getting.Lefty
The inductor is not a filter but actually part of the switching system.