External magnetic perturbations can be used in tokamaks to mitigate edge localized modes [1] and/or to influence the neoclassical tearing mode island dynamics in order to optimize ECCD stabilization [2]. On the other hand, the perturbation can produce flow braking with negative effects on plasma confinement. It has therefore high relevance for the tokamak community to understand the underlying physics related to the plasma flow braking by an external magnetic perturbation. The braking can be due to the interaction of the static perturbation resonant harmonic with the rotating plasma mode [3] and/or to the neo-classical toroidal viscosity (NTV) torque due to the non-resonant harmonics generated as side-band effects related to the small number of active coils [4]. This work will aim to quantify the effect of non-resonant magnetic perturbations (non-RMPs) on the plasma velocity. The first part describes the experimental study on EXTRAP T2R reversed-field pinch of the plasma flow braking due to non-RMP. The second part of the work compares the braking torque calculated from experimental data with the torque expected by the neo-classical toroidal viscosity (NTV) theory [4,5]. A clear study of the plasma braking effect is relatively complicated in tokamaks because of the limited number of active coils that inevitably produces a broad spectrum of side-band harmonics. On the contrary, the feedback systems installed in EXTRAP T2R has the capability of suppressing the entire RWM and error-field spectrum and simultaneously producing a clean external perturbation [6,7]. An example is shown in figure 1(a), where the Figure 1. Frame (a): radial magnetic field at the plasma edge. The blue line corresponds to the non-RMP harmonic (1,-11). Frame (b): time evolution of the TM velocity (red) for the innermost resonant harmonic and of the line integrated OV velocity (blue). Frame (c): Profile of the TM velocity shift during the non-RMP.