If your plane uses a brushless motor, you will need a brushless ESC. If the motor is brushed, the ESC must be brushed.

The current rating of the new ESC should be the same or larger than the original ESC. For example, if the original was a 20A ESC, the new one must be 20A or larger.

The new ESC should have a low voltage cutoff (LVC) feature for the type of battery (Lipo or NiCd/NiMH) that you will be using.

- Jeff