SMALL BRASS ROUND INSET FLANGE ESCUTCHEON keyhole cover key insert thread. External diameter max at top edge 22.8mm reducing to 20mm. Depth max 7.1mm. Keyhole length 12mm & width 4.2mm. Disassembles into three parts. The actual part where the key would be inserted is again brass and about 0.75mm thin. Any questions please ask.