Makes braking and shifting super smooth by reducing the drag in cable housings. Shops worldwide won't build or repair without using Cablemagic. This stuff works so well we were shocked at how well it has gone over with the bicycle dealers. It is very easy to use: drip it into the cable housing, wipe some on the cable then put everything together. Use it with non-coated cables. Coated cables somehow don't last as long with any lube in the housing. So many dealer and team mechanics have called us to say that they will never use a coated cable now that they use Cablemagic.