The ring refers to the position your hand can take when you give your lover a blow job.
Most girls hate it when the penis enters their mouth too deeply, since it creates a gagging reflex.
Avoid the penis from going in too deep by holding the bottom of the shaft with one hand.
With your other hand you form a ring with your index finger, middle finger and thumb. Tuck your lips around your teeth and place the ring as close to your mouth as possible. Wet your fingers with saliva beforehand, because a good blow job requires it to be slippery.
While you let the penis slide in en out you can twist the ring to the left and right for extra stimulation.
The ring gives the guy the illusion you take his penis far deeper into your mouth than you actually do.
The tighter the ring, the quicker your lover will come.