1. Activation of RSS Pull up the vulcanized black rubber edge of the bezel. This releases the lock of the Rotation Safety System and with it the upper black ceramic ring with the minute scale. When activated, a stainless steel ring appears around the edge of the top ring. 2. Setting the dive time measurement With the stainless steel ring now visible, turn the top ring counterclockwise and place the marker at the position of the minute hand to read the dive time. 3. Save the time setting When in the correct position, press down on the top ring until it clicks into place. The time scale is now secured and the dive can begin.