Product review (5 stars): Good switch / fuse protection package
Nice package - as mentioned by other reviews this does not include the fuse, or instructions for connections.
The switch is a two pole single throw switch. One pole is between terminals 1 and 1a, the other between terminals 2 and 2a.
There is a light powered from terminals 1 and 2.
To connect so as to have the light on constantly - so the light helps you locate the switch regardless if it is turned on or not, or indicates that there is power connected to the switch - connect the incoming power (L and N) to terminals 1 and 2. When the switch is turned on, it will output the incoming voltage to terminals 1a and 2a.
To connect so as to have the light come on only when the switch is turned on - so the light lets you know whether the switch is turned on or not - connect the incoming power (L and N) to terminals 1a and 2a. When the switch is turned on, it will output the incoming voltage to terminals 1 and 2.