Samsung introduced SmartTag and SmartTag + beacons earlier this year. Both models have the same usage scenarios in general, but the second features support UWB (Ultra Wide Band) technology for more accurate positioning.
And only now SmartTag + finally goes on sale. According to the source, the beacon can be pre-ordered in B&H stores for $40. Sales should start on April 12th.
The regular SmartTag model now sells for $25, but it only uses Bluetooth.