Through Authenticate 
POWER MACARONI
Fitting on cable stopper of down tube(for road bike aero bar)
●Adjust the cable loose and tight, to solve the road front derailleur before the car can not adjust the trouble
●Keep distance between cable and frame to prevent both scrape
●Self-swing direction when handlebar turns
Fitting on rear derailleur：
●Prolong cable life
●Ensure derailleur work freely Weight：4 g / pcs
