What does xh mean on hp printers?

xm = Duplex, Extra tray, Network and Mailboxb = Batterybt = Bluetoothbm = Book Makerd = Duplexdt = Duplex and Extra Traydn = Duplex and Networkdtn = Duplex, Extra Tray and Network (Now "x")× = Duplex, Extra Tray and Network (Formerly dtn)xh = Duplex, Extra Tray, Network and...