There are three types of men's USTA Pro Circuit events: ITF World Tennis Tour 15s, offering $15,000 in prize money and ITF World Tennis ranking points; ITF World Tennis Tour 25s, offering $25,000 in prize money and both ITF World Tennis ranking points and ATP ranking points; and ATP Challengers, offering between $50,000-$150,000 in prize money and ATP ranking points.
https://www.usta.com/en/home/pro/pro-tennis-events/pro-circuit.html