Sexual arousal is the major factor in erectile function. Sexual arousal releases NO (Nitric Oxide) from the nerve endings supplying the penile arteries, resulting in a rapid and very marked increase of blood flow into the penis. Adequate blood flow is everything where an erection is concerned. Couples are advised to explore with each other all available sexual aids that could improve blood flow to the penis. Some options include videos and devices such as vibrators, lubricants and penile rings. carries a very wide choice of these aids. Their Better Sex Video Series has instructional DVDs such as “Better sexual techniques”, “Advanced Sexual Techniques” and “Making Sex Fun”. This site is provided and managed by the Sinclair Intimacy Institute. Their Advisory Council comprises an impressive array of academic and practicing doctoral level experts in sexuality and sex therapy. They donate over one-third of their profits to DKT International, a worldwide organization promoting family planning and aids/HIV prevention.