The difference between Gri Gri and Gri Gri plus is that the GRIGRI + can handle ropes between 8.5mm and 11mm in diameter, providing optimal performance with ropes between 8.9mm and 10.5mm but the gri gri is made for ropes between 8.9mm and 11mm, and is optimized for ropes between 9.4 and 10.3mm.