What size hex head to remove front callipers?

The only hex heads I have to remove the bolts holding the calliper on are 8mm and 10mm, no standard sizes. Anyone know the specific size of the hex head? Just trying to save trips to get the right tool.

Thanks.

3/8" allen, IIRC.

Thanks for the reply. I thought I had tried that size but maybe not. I'll try it again when I change the fuel filter tomorrow.

Thanks.