I was missing a screw too out of one of my two FOB's. I found a suitable replacement at True Value - the better stores have a pretty comprehensive fastener section. It's in the metric area, it's an "M2-6" slotted. Not an EXACT match, it's alittle short and it's slotted, but it DOES work. The "M2" part of the equation is the thickness/thread pitch (I believe) and the "6" part is the length. .29 cents plus tax - I would have bought YOU one, but it was the LAST one in the bin - I'm guessing that it's a pretty popular size with the key FOB crowd!