Installation is easy and only requires 5mm and 6mm allen keys. Simply remove the derailleur from the existing hanger, fit the extender in its place through the top hole (as per picture), and attach the derailleur to the bottom hole of the extender.
GT Bikes Rear Derailleur Hanger - Fits a Range of Models WITH FIXING BOLT
Boardman Bikes Rear Derailleur Hanger / Dropout Hangers Alloy
HOUSON bicycle rear derailleur, rear derailleur 7/8/9 speed bicycle rear rear wheel gear bicycle derailleur for MTB bikes
Burton Bikes PF30 386EVO bottom bracket press tool, bearing installation/removal
1pc Rear Derailleur Hanger, Bike Gear Hanger Cycling Bicycle Aluminium Alloy Rear Gear Mech Derailleur Hanger Hook Dropout Frame Forme Bike Derailleur Hanger for Most Bikes(289)
1pc Rear Derailleur Hanger, Bike Gear Hanger Cycling Bicycle Aluminium Alloy Rear Gear Mech Derailleur Hanger Hook Dropout Frame Forme Bike Derailleur Hanger for Most Bikes