Depends on the model. For instance some models like the IPV05 are manual on only, the IPS05 will act as manual on if the ambient light level dial behind the face of the device is set to 0.

There are also models that have a set of dip switches that one switch that controls the vacancy/occupancy operation.

Depends on the model. That looks like an IPS05 or and IPV05. The IPV05 is manual on only, the IPS05 will act as manual on if the ambient light level dial behind the face of the device is set to 0.

There are also models that instead of dials have a row of tiny slide switches called dip switches that control the vacancy/occupancy operation and the on/off time delay.

The sensitivity dials or dip switches are usually located behind the pushbutton. If it is an IPV05/IPS05 to access the controls first you need to remove the trim cover, then gently push down and pull forward on the tiny tabs that on the top of the plastic that hold the button assembly to the switch.