The tube that carries the sperm is cut and then tied or cauterized. This prevents the sperm from being ejaculated. Must have two test before sterility guaranteed. Varies depending on your location. There are costs for visits, surgery, sperm counts, and other lab procedures.
Some insurance policies do cover the procedure.
One time decision, doesn't interfere with erection or ejaculation. No known side effects. Doesn't interfere with spontaneity. Surgical procedure required. Some discomfort at the time of procedure.