Weapons with the chained fusion gain a short chain that dangles from the haft or handle. The chain magically extends to enable the weapon to attack foes beyond the wielder’s immediate reach. A chained weapon gains the reach weapon special property for the first attack made with it each round.
After it has been used for an attack, the weapon loses the reach weapon special property until the beginning of your next turn. You can add this fusion only to melee weapons.