they used to be amyl nitrate, until it became illegal to sell. Sometimes they sell it as vcr head cleaner or leather cleaner but it is not really intended to be used as such. Amyls increase the amount of oxygen your blod can carry for a short period of time causing muscles to relax and a head rush. I've heard they still work the same way, cuz they're still similar chemicals, but I've never tried them so i wouldn't know.