**Taken from google**
The Samsung Galaxy SmartTag 2 represents a significant upgrade over the original SmartTag, primarily due to its enhanced tracking capabilities with Ultra Wideband (UWB), longer battery life, and a more durable, user-friendly design
Tracking Technology:
The SmartTag 2 utilizes both Bluetooth Low Energy for long-range tracking and Ultra Wideband (UWB) for pinpoint accuracy when finding lost items nearby.
The SmartTag 2 offers significantly improved battery life, with Samsung claiming up to 500 days on a single battery and potentially 700 days with power-saving mode enabled
The SmartTag 2 is IP67 rated, making it dust and water-resistant (up to 1 meter for 30 minutes), a step up from the IP53 rating of the original
The SmartTag 2 offers features like Compass View and Search Nearby for easier item localization, as well as the ability to control compatible smart home devices
Design:
The SmartTag 2 features a pill-shaped, sleeker design compared to the square shape of the original, with a larger, more durable metal loop for easier attachment.
https://www.androidpolice.com/samsung-galaxy-smarttag-2-vs-galaxy-smarttag/