Ant2 uses a popular Microchip MCP73831 in a DFN package, which reduces thermal throttling. The more common SOT-23-5 package has a thermal performance about three times worse than that of DFN. Thermal throttling increases the charging time because of the reduced charging current. By improving the thermal performance the risk of increased charging time is reduced.
Despite its tiny size, Ant2 can be mounted using regular M3 or M2.5 screws. Two half-cut mounting holes on each side provide a compact but still reliable mounting.