Catalogue entry no. 506 by Max Loehr:
506 Openwork Plaque (Fragment of a Hinged Pair or Set?)
Light gray, russet, and dark brown jade plaque of roughly oval outline. Two larger dragons with turned heads flank a central small dragon set between two rectangular, slotted frames. This small dragon, in headlong position and asymmetrically designed, has a bird’s head and criss-crossed scales, like feathers, on its neck. The rest of its body is marked, like the bodies of the larger beasts, by finely incised curls, cross-hatched areas, and striae. The incised designs are identical on both sides. It is the irregular shape and cruder finish of this larger rectangle, bottom center, that indicated the likelihood of its having been linked by a ring to an analogous plaque, which is lost. Late Eastern Chou.
The surface incisions closely resemble that of No. 502.