The purpose of a sperm stopper is the allow a constant pressure on the glands on the underside of the penis to intensify each touch, stroke, ect..
This item is not a chastity device and does not prevent an orgasm.
This toy can be used alone or with a partner. It is important to be comfortable with understanding the use of the toy before using.
Simply slide the head ring over the tip of the penis, the toy can be used facing up or down, and slowly insert the ball head into the urethra. Lube is not necessary but it is recommended if there is trouble inserting the ball.