Filament Run Out Sensor screw size

Anyone know what the size screw that holds the filament runout to the tool head? I dropped it inside the machine and then it fell somewhere, because my dumbass didnt decide to just remove the screw all the way after I remove it from the printer. Was changing it for the Qidi box which sucks because I cant use it now.

I assume its a M2.5 but I wanna double check