The Samsung SmartTag looks just how you’d expect it to – CNET
Samsung SmartTag and SmartTag Plus can be attached to frequently lost items such as keys, purses and backpacks. If you lose them, you can use your phone to track the position of the SmartTag and thus the missing item.
The regular SmartTags use Bluetooth and will work with pretty much any Bluetooth-compatible Samsung phone from the last few years. The SmartTags Plus use ultrawideband wireless, are more expensive and are only compatible with the Galaxy S20 and S21 family of devices.