User blog comment:Xilinoc/Ch. 571 (Yachiru's gonna wreck it)/@comment-11446176-20140305130913/@comment-10205398-20140305143836

"Despite not knowing its name, Kenpachi's Zanpakutō is constantly in its released state, much like Ichigo's Zangetsu. He obtained this state while still a child. The blade is much longer than a standard Zanpakutō's, roughly the size of a nodachi, with a guard which extends inward from its center, similar to a shinai. The hilt is white, though most of it is wrapped in bandages, as is his sword's sheath. Its released states comes from Kenpachi's overwhelming Reiatsu forcing the release, rather than from knowing his blade's name. Despite constantly being in Shikai, Kenpachi's Zanpakutō does not grant him any additional abilities, due to their lack of communication." [[Source]http://bleach.wikia.com/wiki/Kenpachi_Zaraki]