At only 6 grams the token chain drop catcher prevents the chain from damaging your frame when the chain falls off the rings of your road bike it may be a simple piece of metal but it could save you a lot of tears and the cost of a new frame simply attach it to the front of your derailleur with the supplied bolt which comes in a matching colour and hit the roughest roads you want without fear the chain catcher is available for double and triple chainrings to