Derived concentration parameters from the profiles based on the noise-free source sample (dashed gray line) vs. halo masses compared with the concentrations obtained using the Duffy et al. (2008) relation (solid red line). The gray area corresponds to the errors in the fitted concentrations. The red area is computed according to the errors in the parameters of the relation reported by Duffy et al. (2008). Fitted concentrations are well constrained for halos with masses lmhalo > 12.5 log(M/M_⊙), but predicted concentrations using the relation by Duffy et al. (2008) are about twice the values obtained by fitting this parameter.