Nightwatch Helm

Wondrous item, rare (requires attunement by a fighter)

This sturdy steel helm helps keep you watchful and awake when on guard. You have darkvision out to a range of 60 feet. If you already have darkvision, the nightwatch helm increases the range by 60 feet. In addition, you have advantage on saving throws against effects that would cause you to fall asleep. When you would gain a level of fatigue, as a reaction you can negate that fatigue. Once you use this property, you cannot use it again until you complete a long rest.