The original and genuine automatic chain lubricating system.  Over the years, Scottoilers have saved bikers thousands of pounds in chain wear.  This is probably one of the best investments in biking, certainly in terms of ROI.  Chains are expensive and no matter how assiduous you are in your chain maintenance, there is no substitute for a constant drip feed of lubricant that takes away the dirt and grit as it tries to accumulate.  As the old saying goes "Keep your chain clean, don't keep cleaning your chain".