Weight is 4.025g. Diameter 22mm +/- 1mm. Thickness 1.5mm +/-0.5mm. Composition unknown.
From what I've seen on Google, the Qing Dynasty made coins like this and later on the Javanese started copying them to hang on strings to make them easier to transport. I suspect this might be the latter but I can't find an exact match for this coin though so it's hard for me to know exactly what I've got.
Any thoughts on the country of origin, age and value of this coin are much appreciated!

