Double
Source: Ultimate Combat, p. 45
dire flail, dwarven urgrosh, gnome hooked hammer, orc double axe, quarterstaff, and two-bladed sword Firearms: all one-handed**, two-handed**, and siege firearms** Flails: chain spear*, dire flail, double chained kama**, flail, flying blade**, heavy flail, kusarigama**, kyoketsu shoge**, meteor hammer**, morningstar, nine-section whip**, nunchaku, sansetsukon**, scorpion whip**, spiked chain, urumi**, and whip