helmet of brass - The Philistine helmet had the appearance of a row of feathers set in a tiara, or metal band, to which were attached scales of the same material, for the defense of the neck and the sides of the face [Osborn].
a coat of mail - a kind of corslet, quilted with leather or plates of metal, reaching only to the chest, and supported by shoulder straps, leaving the shoulders and arms at full liberty.