With the Wonder Core 2 Rowing Kit PRO you can make your workouts even more intensive. The original rowing set of the Wonder Core 2 has a resistance of about 4.5 kg per side. The PRO rowing set doubles this number up to 9 kg. As an advanced athlete you can challenge yourself further and become stronger. The Wonder Core 2 rowing set PRO can only be used in combination with the Wonder Core 2.Note: The fixing bolts for the rowing set are already attached to the Wonder Core 2 and are therefore not included with the rowing set.