The page does not seem to list any specifications for the connector. I noticed that they also offer EverDrives, but I have no idea whether that's legitimate.
@EvilDragon, do you know anything about Tototek?
Before I built my prototype, I spent many hours trying to find a suitable connector, and I only found the NES spare part. I hope that EvilDragon will be more successful.
For a new prototype, if I get around to making one, I will use sawn-off pieces of shorter connectors.
Note that I am also aware of the threads on the Nesdev forums where people discussed the use of connectors with the wrong stride. I guess, if you can ensure that the cartridge is centered properly, and if the connector has narrow contacts, it may work. But I'm not a fan of such a solution.