Guyana to Australia: You'll need an adapter
You'll need a plug adapter: Guyana uses Type A/B/D/G, Australia uses Type I, and they don't fit. Voltage is compatible (220V vs 230V), so any dual-voltage or matching device is fine either way.
You'll need a plug adapter: Guyana uses Type A/B/D/G, Australia uses Type I, and they don't fit. Voltage is compatible (220V vs 230V), so any dual-voltage or matching device is fine either way.