0.001 metres.
The smallest BB is 4.5mm. As far as I know there is no 1mm BB gun.
0.7
1mm 1mm
1mm
0$-$1MM+
Define the measurement
1mm converts to 0.000001km
1/10cm=1mm
1mm. per year
How thick is it
If the circle has a RADIUS of 1mm then about 3,14 mm2 If the circle has a DIAMETER of 1mm then about 0,785 mm2