Sword Two Bladed

A two-bladed sword is a double weapon’ twin blades extend from either side of a central, short haft, allowing the wielder to attack with graceful but deadly flourishes.

A two-bladed sword is a double weapon. You can fight with it as if fighting with two weapons, but if you do, you incur all the normal attack penalties associated with fighting with two weapons, just as if you were using a one-handed weapon and a light weapon. A creature wielding a two-bladed sword in one hand can’t use it as a double weapon’ only one end of the weapon can be used in any given round.

Weapon Feature(s): double

Two-Handed Melee Weapons (Exotic)
Weapon	Cost	Damage (S)	Damage (M)	Critical	Range Increment	Weight	Type	Special
Sword, two-bladed	100 gp	1d6/1d6	1d8/1d8	19-20/×2	–	10 lb	Slashing	double

Source: Core Rulebook