What's in the box:

1 X Lixada Portable MTB Mountain Bike Speed Bicycle Bike Rear Derailleur Converter Cycling Tail Hook Extender (black), Black

Adding this product in the bicycle dial hook the converter, you can easily solve the troubles you encounter.

Features:
The derailleur hanger extension is a unique device that offsets the position of your road derailleur to make it possible to run a wide-range mountain bike style cassette.
Aluminum alloy material, CNC workmanship, solid and firm, enduring and long time to use.
This product is used for rear derailleur extension, apply mountain freewheel 10-11, 40T, 42T, 46T/ 50T / 32T / 36T Road flywheel.
Expand the flywheel speed change more smoothly.
Adding this product in the bicycle dial hook the converter, you can easily solve the troubles you encounter.
It is great for riders with double chaining bikes that want lower gearing for those ultra steep climbs.
Great accessory for cycling enthusiasts.

Specification:
Material: Aluminum Alloy
Color: Red / Black(Optional)
Size: approx. 4.5 * 1cm/1.8 * 0.3in
Hole Diameter: approx. 1cm / 0.4in
Screw Diameter: approx. 0.5cm / 0.1in
Weight: 11.2g / 4.4oz
Package Weight: 12g / 4.7oz

Package List:
1 * Piece Cycling Tail Hook Extender
1 * Piece Screw

Tip: The bike rear derailleur hanger has different size, doesn't match perfectly. You need to polish the bottom of the tail hook.