30% increased Stun and Block Recovery
10% chance to gain an Endurance Charge when you Stun an Enemy with a Melee Hit
10% chance to double Stun Duration 
Stun Mastery is a notable passive skill that grants increased stun recovery and reduced enemy stun threshold. It also grants a chance to gain an Endurance Charge when you stun an enemy with a melee hit and a additional chance for double stun duration.