1 1/8 diameter of slightly more domed shape.
Concentric circle decoration with a band of alternate hatched triangles and circles. Stained blue when made. Few small edge chips.
It was found in York, England area and sold at Philips Auction House London, in the 1980's.
The fourth stirrup strap mount is a British find and a rare type in the (Anglo-Scandinavian) Urnes style with entwined beasts, measuring 45 mm x 38 mm