Remote location works through Apple's 'Locate' network, which uses nearby Apple devices to detect the AirTag and transmit its location via iCloud. So even if the object is in another city, its position can be updated as soon as an Apple device passes near the AirTag and relays its location. No additional subscription is required for this service. On the other hand, direct Bluetooth communication between the AirTag and your device is limited to around 50 metres, but the "Locate" network makes it possible to exceed this limit by using the millions of Apple devices around the world to locate the AirTag remotely.

Yes, the Apple AirTag (4-pack) with the model number MX542ZM/A also works abroad. The AirTag is IP67 rated.

Thank you for your reply.
Does it also work abroad?
Is it waterproof?