Datasheet

The maximum length and width of the Leonardo PCB are 2.7 and 2.1 inches respectively, with
the USB connector and power jack extending beyond the former dimension. Four screw holes
allow the board to be attached to a surface or case. Note that the distance between digital pins
7 and 8 is 160 mil (0.16"), not an even multiple of the 100 mil spacing of the other pins.