They are very strong, the grip is good, and the diameter and just perfect.
The only small problem lies in the leaflet that is nonexistent.
For those still struggling, we must don the "cable" backwards, otherwise it does not lock when you step on the rings you slide along the cable.
While at the back is perfect.
Do not hesitate to seek some explanatory videos on Youtube in English if you are really arrive.
Type "killer elite rings".
