I purchased these wonderful devices for my boyfriend and I used them on his beautiful but small man nipples during foreplay. Each time I would leave them on longer and longer during sex play and although he said they hurt his cock erection was incredible. He was most excited. When I removed them his nipples would stiffen almost a full inch and it became thick and firm--very exciting to me and he loved it when I would tickle, pinch, kiss or suck them and he loved the pleasure of his tight shirt rubbing on them. He is built like a brick wall and his now massive and assertive nipples make him look like a greek statue. I am so pleased at the results on my bf's perkey nips. Oh--he sez his headlights are more sensitive than ever!