Beats me.
I just picked 'em up 'cause they were $6.95 Universal LNBs.
Got 'em from IvyStonePlace last year to have around to play with.
He's a DMSI reseller, and apparently these were left overs or close outs, or maybe the remnants of a big sale to Sky Mexico.
Wasn't too happy with the shipping and handling, as I had to buy four to get the total price down, but they wound up around $10 each, and seem to work fine.
Linuxman has run a couple of pretty nice threads on mounting two of 'em on each of two dishes, to watch four birds, so I guess they were passable.
87W and 97W with Primestar 84e Multi-LNBF
123w and 129w with 1 Meter Primestar
(had a heck of a time posting these links... wonder if they're working on the server again?)