This set of 10 screws (diameter 2.5mm) and 5 corresponding threaded spacers (7mm height) is ideal for fixing Yoctopuce devices in a box or on a support. The exact position of the fixing holes on the devices is documented in the technical schema available with each device. If you plan to mount your Yoctopuce device in a Yoctopuce enclosure, you do not need any Fix-2.5mm.
If you prefer to use your own screws rather than these, make sure that the diameter of the screw head is not larger than 4.5mm. Larger heads could damage the boards.