Ulak Blades (3.5e Equipment)
From D&D Wiki
Ulak Blades are the native weapons of the Furyans, designed for two-weapon close combat fighting. Ulak Blades are always made in pairs.
Wielding a pair of Ulak Blades gives a circumstance bonus of +2 to Climb checks (or +1 if only one blade is wielded.)
Monks may use this weapon as a special monk weapon.