The Sunrace MTB 6/7V 13-28D rear derailleur is easy to handle and very aesthetically appealing with an interesting design. This derailleur is designed for mountain bikes. The product is composed of aluminum and steel and is compatible with 13 to 28 T cogs, up to 7 gears.Sunrace products have an excellent value for money and are also very robust and of a high quality. This is a reliable brand that you can always build on when you want to refurbish or improve your bike.