2 seals per side, any bike shop who deals with Cykel / Link can supply them. I prefer to use a slightly wider one on top.
Ariete part numbers:
53-063-00 (40 x 52 x 8/10.5)
53-033-00 (40 x 52 x 8/9.5) Link part number for this one: 33-129-31.
You will need to buy 2 sets of the narrower one (std for 40mm Husky) or 1 set of each.
Cheers,
K