it looks like the approx. 18 cm long trisula's made from tombak ( alloy of copper and zinc) as many of the trisula's from Java and Sumatra, popular with the Betawi warriors and the in Srivijaya (Indonesian: Sriwijaya) empire.
Still used in Pencak Silat:
https://www.youtube.com/watch?v=q88UBDQaT8k