An English Harquebusiers Breastplate, With raised neck and medial ridge terminating in a point at the waist, which dips down to the centre and has a narrow flange. The neck and arms edges have plain inward turns and decorated with double border line engraving,  At either side of the chest are pierced studs for fastening the shoulder straps. 

External Marks: 

None visible 

Internal Marks: 

None visible, although a section of the plate has come away suggesting the breastplate is of duplex construction, see:

Anthony de Reuck, David Starley, Thom Richardson & David Edge, `Duplex armour: an unrecognised mode of construction`, Arms & Armour, Vol. 2, no., 1, Royal Armouries Museum, Leeds, 2005.