Firma 120A Brushless Smart ESC for 3S-4S Surface Vehicles (SPMXSE1120)

Firma 120A Smart Brushless ESC for 3S–4S surface vehicles is a high‑performance electronic speed controller that sits at the heart of Spektrum's Firma Smart ecosystem. It pairs precise power management with built‑in telemetry, streaming RPM, voltage, temperature, and capacity data to a compatible transmitter over a single wire for real‑time monitoring and on‑the‑fly tuning.

Designed for 1/8‑scale surface vehicles running on 4S LiPos, this ESC is compact and waterproof, with a rugged plastic case, mounting tabs, an aluminum heat sink, and a cooling fan to keep temperatures in check. It provides multi‑point protection (over‑current, LiPo low‑voltage cutoff, thermal, and failsafe), an adjustable high‑current BEC (6V or 7.4V up to 4A), and backwards compatibility with EC3/EC5 connectors. Firmware updates are available via the Smart ESC Programming Box or PC app, and setup is ready to install with no soldering required. A limited 1‑year warranty backs the unit.