I think this is the part number: ROC-530068 Roche ULP Screw M3 x 6,0mm. I think they where mentioned in this thread earlier. But you could use any low profile/half thread screw. The Roche screws are steel but if you want an aluminum version or a longer screw you could use a Tworks set as they have versions up to 10mm (TW-ASS-306LPS T-Work´s Aluminum 7075-T6 Hex Socket Head Low Profile Half Thread Screw 3,0 x 6,0mm)