These are the very small screws which you'll see mounting truss rod covers in place on the headstock

I doubt they're a "Universal" part to be honest, purely because there are so many guitars, with so many truss rod covers, so its worth double checking that you do, indeed, need a #3 screw with a 1/4" thread - but, beyond that? Its fairly plain sailing.

Quantity - 2
Weight - 1g
Material - Steel
Thread - #3mm x 1/4" (2.3mm Thread Diameter - Thread Length - 6.35mm)
Head - Round Head Phillips
Head Diameter - 4.5mm
Total Length - 8mm