At the moment there are 6 different steelbooks for Final Fantasy XV and Kingsglaive: Final Fantasy XV
Final Fantasy XV Ultimate Collector's Edition steelbooks (SE Store exlucive; EU, NA)
https://store.eu.square-enix.com/eu/...-s-edition-ps4
Final Fantasy XV Deluxe Edition steelbook (EU, NA)
https://store.na.square-enix.com/pro...xe-edition-ps4
Final Fantasy XV Special Edition steelbook (AUS, ESP, FRA)
https://www.mightyape.co.nz/product/...n-ps4/25249872
https://www.amazon.es/dp/B01GJDT7GE/
https://www.amazon.fr/Final-Fantasy-...dp/B01I38STMQ/
http://www.zavvi.com/games-ps4/final.../11356706.html
Kingsglaive: Final Fantasy XV steelbook (2 discs)
https://www.amazon.co.uk/Final-Fanta...nal+Fantasy+XV
Is there more...