The 14th Century Spaulder

de bene esse: literally, of well-being, morally acceptable but subject to future validation or exception

 1349

The spaulder—a piece of medieval plate armor that protected “the wearer from unexpected and unseen blows from above”.

The term spaudler appears to be an anglicized version of the word espaulier, which is found frequently in English documents from the early 13th to the early 14th C. It appears to have originally been some sort of padding for the shoulder. The earliest noteworthy defenses for the shoulders in 1320  were protected by what appear to be decorated roundels that face forward, with the elbows  similarly protected. These items are presumably laced to his maille. There are no known surviving spaulders from the 14th C.  At no time is it clearly shown how the spaulders actually attach to the shoulder, the details usually being obscured by other elements, though it is assumed that they are “pointed” to the aketon (padded garment worn beneath the armour) or possibly laced to the maille beneath. 
Development of the 14th Century Spaulder

Today's so-called "surveillance spaulder" alerts the wearer to also unseen, albiet electronic, attacks.

The New Armor That Lets You Sense Surveillance Cameras

theatlantic.com

Like a creepy digital tap on the shoulder