Actually, I think it's more like 350%
Fallbrook does not give a percentage, just states it is comparable to other internal hubs.
Sheldon Brown has it listed as 250%. It doesn't feel like it's more than 250%.
Originally Posted by Sheldon Brown's Gear Calculator
For 26 inch (nominal) tire with 170 mm cranks and 20 tooth sprocket
42 / 20
1.75 95.6
250.0 %
0.5 27.3
With NuVinci continuously-variable range Hub