Sarawak Rangers officer’s gilt uniform button, large size, 25mm diameter.
The Arms of Sir Charles Johnson Brooke, Rajah of Sarawak, with the inscription ‘Sarawak Rangers’ around the upper perimeter.
This example by Hobson & Sons, Lexington St. London W.
The motto ‘Dum Spiro Spero’ = ‘While I breathe, I hope’
Note: Sarawak did not become a Crown Colony until 1946, this button probably pre-dates this period.