The first OBU will be installed free of charge for existing Singapore-registered vehicles. Due to the impact of COVID-19 on global supply chains, the installation exercise will commence in the second half of 2021 and take place over a period of 18 months.

You can read more about it here: https://www.lta.gov.sg/content/ltagov/en/newsroom/2020/9/news-releases/installation-of-on-board-units-for-next-generation-erp-system-to.html#:~:text=3%20The%20first%20OBU%20will,a%20period%20of%2018%20months.