The S1-200 controller can be mounted to a wall or other flat surface.
You will need 2 x screws that are appropriate for material your are fixing to. The screws shoud be 20 mm [3/4"] plus the depth into the wall or mounting material. M3.5 x 40 mm [#6 x 1-1/2”] screws are normally sufficient.
Note: The screws supplied with the controller are for mounting to the underside of a PV module and not for wall mounting.
For installation on the underside of the solar module, see the following link: