(Note: Measurements are outside max. dimensions unless stated otherwise).19th Century : Hollow raised Sphynx head patera with flat rim.Diam. 56mm. (2 3/16")Height 13mm. (1/2")Single central tang on reverse.It is recommended that if selecting screw thread option, a pilot hole is drilled and pre-cut with a steel screw of slightly smaller size before screwing in the casting to avoid shearing.