Consider a rigid solid sphere falling with a constant velocity in a fluid. The following data are known at the conditions of interest: viscosity of the fluid = $0.1\:Pa\;s$, acceleration due to gravity = $10\:m\:s^{-2}$, density of the particle = $1180\:kg\:m^{-3}$ and density of the fluid = $1000\:kg\:m^{-3}$.The diameter (in $mm$, rounded off to the second decimal place) of the largest sphere that settles in the Stokesâ€™ law regime (Reynolds number $\leq 0.1$), is ______________