Seat is absolutely like new; looks like it just came out of the box. Original purchase date was 11/21/19; sales receipt in hand and will go with it. I just bought it from the original purchaser, who sold his Heritage and hung onto this seat; not sure he even used it, doesn't look like it. So, before I installed it on my '19 Heritage, I have also decided to sell mine as well, so will have no need for the seat/backrest.
H-D Part # is 523000290 for the seat, and 52300409 for the backrest. Per the H-D description, the seat fits '18 & later FLDE, FLHC, FLHCS, FLSL, FXBB, and FXST. The seat is one-piece, has an internal sling system (hence the Hammock name) for support and increased suspension. Seat lists for $529.95 and Backrest for $149.95 - $679.90 for both. NOTE: Per the H-D website, these are NOT currently available, so availability is very limited.
I'm just looking to get my money back; got a pretty good deal on it; pass it on to someone who wants to try one and not break the bank on a new one, which apparently you can't get anyway at this time.