Armour of steadfastness.

This armour appears to be made of a light cloth. When activated, the cloth takes on the appearance of scales, shell or segmented metal. 
It grants a +1 to AC. 

When you are attuned to the armour, you can speak a command word as a bonus action. 
For the next minute, you cannot be moved against your will, and checks to grapple you are made with disadvantage. 

After this feature is used, it may not be used until you complete a long rest. 

Made from tough but flexible leather, studded leather is reinforced with close-set rivets or spikes.