Duelling Gloves is a passive feature that grants a bonus to single handed melee weapons.
Description
While only holding one weapon in your main hand and nothing in your free hand, gain a +2 bonus to melee weapon 
Attack rolls.
How to learn
Granted by the equipment:
Notes
- Despite the description stating an empty off-hand is required, the bonus from this effect is still applied if a shield is equipped, functioning the same as the Duelling fighting style.