The Sky Power 100 Amp OPTO Electronic Speed Control is a good choice for many medium to large brushless motors.and is designed to be used with 2 - 6 cell lipo batteries.
The Sky Power 100 Amp OPTO ESC comes with 4.0mm female bullet connectors installed. The battery connector is a male T-Plug.
This ESC has NO Battery Elimination Circuit (BEC), so you will need a receiver battery pack or a Universal Battery Elimination Circuit (UBEC) to power the receiver and servos. This is a safer way to go on large models for the following reasons:
1. Most built-in BEC circuits are 1 to 3 amp 'linear' circuits which are only useful for 2 or 3 standard size servos when using a 3 cell Lipo battery. If you use more servos, or a higher voltage battery pack, you will almost certainly overload the BEC of the ESC, causing a crashed model.
2. In an ESC with a built-in BEC, excessive heat generated in the ESC by the motor current and/or BEC can cause total loss of power to the receiver/servos, resulting in a crashed model. The chance of total loss of power is greatly reduced when a separate receiver battery pack or UBEC is used. If the ESC overheats and shuts down (no power to the motor), you will still have power to the receiver/servos, and will be able to maintain control of the model.
3. In an OPTO ESC, the motor control circuitry is isolated from the line to the receiver, so the chance of glitches caused by motor noise is reduced.
Several programming options can be set with your transmitter or a program card, but no programming is needed for most applications.