Omtaler

MARS: ( Micro Adjustable Resistance System. ) This system was developed to more precisely regulate rolling speed for training. It is not as user friendly for down hills as the ATRA. The ATRA can be instantly engaged to one of four resistance positions, while with the MARS you must stop and turn the knob to the desired position. Fits 900 and 800 series skis.

One speed reducer is needed for each roller ski. Sold Individually.

Download instructions for ATRA & MARS speed reducers