These controllers are unmatched in their price class, and even outside their price class! Up to 40% more FETs than similarly-rated ESC from other makers, and those FET are higher-quality fast-gate type. That means that you can push the ESC harder without fear - up to 40% over their rated continuous current shorttime - and performance is higher at all throttle settings due to low intenal resistance. With an inexpensive programming card, you can choose settings for battery type (Lipo/NiCd-NiMH), startup, braking, frequency, timing. Just about everything. The ESC automatically and accurately set cell count for lithium packs 2S to 4S. See Datasheet.