An apparatus that is usable with a well includes a body, a blocking member, a sensor, a radially expandable element and a controller. The body includes a longitudinal passageway that extends through the body, and the blocking member is disposed in the passageway to check fluid from flowing in a predefined direction through the passageway. The sensor is disposed on the body to sense a property of an environment of the string as the object is being communicated through the passageway; the radially expandable element is disposed on the body; and the controller is disposed on the body to selectively autonomously control the expandable element to land the body in a downhole restriction in response to the sensing.