Shimano's Deore XT Front Derailleur sports a lightweight aluminum cage that's chrome plated to reduce wear. This model is specifically optimized for 2x10 set ups. Plus, the body boasts wide parallel pivots that provide fast, smooth and reliable shifts every time.
Bottom-pull derailleurs are used when the cable is routed underneath the bottom bracket and up through the cable clamp. Top-pull derailleurs work with frames where the cables are routed down from the top tube.