Bomb Ring is designed as same as the picture in the official book.
2500yen
Titled "FINAL FANTASY Memorial Collection", the item of FF IV in the series is a package with a telephon card and Bomb Ring ("Package" in FF2us).
I've never seen about it at SQUARE's web site nor Digicube's web site.... Is it for mail-order just at "Fami-Tsuu Bross", a gamers' magagine?
*Note on 2002.12.26 : According to Mr. Souryuukishi, it was sold not only by the mail-order but also in shop and on events.
It seems to be hard to get now.
Pictures by Mr. Souryuukishi. (WebSiteF"DragonKnight-File")