I have a mounted but never shot X400. I have two of these and sold the gun this one was one.
Works perfect and comes with the original box and registration card (it hasn't been registered). You still get Surefire's rock solid warranty. Box is a little beat up but I will include directions and extra batteries.
170 lumen version and March 2011 manufacture date.
$25 shipped CONUS USPS MO or extra discreet PER PACK gift of +4%