Select Class III Firearm Sterling Mk.4 by Kenfix CRITICAL ORDER INFORMATION In order to ship a Class III firearm, RGUNS must have a signed, valid Class III FFL on file.  Submission of a firearm  order without an FFL on file will result in cancelleation of the order.  FFL's may be submitted by mail, fax (847-428-0029) or email (rguns@rguns.net).