A dynamic jump on the wall where all four points of contact briefly leave the rock.
A dyno isn't an arm feat, it's an aimed jump from the legs. The power comes from a pendulum: you load by dropping and rising once or twice from the legs, then release at the turning point. You catch the hold at the so-called deadpoint — the brief moment when upward movement stops before gravity takes over again. For a split second your body is weightless there, and that's exactly when you need the least grip strength. Typical mistake: grabbing for the hold too early instead of waiting for the deadpoint. And very practically — keep looking at the target hold until you have it.