The F1s is a compact model of the F1. It is even smaller and has only one power mode.
Weight: 14.5g
Dimensions: 34mm x 18mm x 29mm
Recovery Time: 0.9s
Color Temperature: 6200k +- 400k
Battery Capacity: 3.7v 128mAh
Battery Life: >300 flashes
Charge Time: about 40min
Input Voltage: 5V/500-2000mA