New front derailleur
There are several criteria when selecting a front derailleur. Top, bottom and now side cable pull. Some Shimano models are both top and bottom compatible. The mount type, seat post clamp mount (correct diameter or have an adapter), bottom bracket mount or direct mount. The derailleur must be compatible with your crankset size. This is usually specified by a maximum number of teeth. It must also match the number of ring gears on the crank (double or triple). It must also match the chain 8,9,10 etc, speed. There is some overlap on 7 and 8 speeds that will work with both.