Because of its size it is suitable for smaller systems.
This transponder has a footprint the size of a business card and at 100g, weigh 30% less than an iPhone. The type of system that might be used by Police or Fire services when the FAA eventually open up airspace for drone flight in America.
Sagetech Corporation is now accepting orders for the new Mode S Transponder with ADS-B Out, which this week was released for production. The Sagetech XP Family of Transponders offers the lightest and smallest transponders in the world, ideal where size, weight and power are at a premium.
Source: sUAS News