eBay

lightly used, Hitec SP-520+ (Plus) Brushed ESC. includes a copy of the instruction manual for easy setup.

The Hitec SP-520 (and its variant, the SP-520 Plus) is a vintage electronic speed controller (ESC) designed for electric R/C vehicles. Released during the era of brushed motor dominance, it is highly regarded by hobbyists for its high efficiency and full MOSFET design.

Key Features & Specifications

Motor Compatibility: Designed strictly for brushed motors. It is not compatible with modern brushless power systems.
Vehicle Types: Commonly used in 1:10 scale (as well as 1:8 to 1:16 scale) electric R/C cars, trucks, boats, and tanks.
MOSFET Technology: Features High-Frequency Full MOSFETs to provide high power transfer efficiency with minimal heat generation.
B.E.C. Plus System: Equipped with a built-in Battery Eliminator Circuit (B.E.C.). This routes power directly from the main drive battery to the receiver and servos, removing the need for a separate receiver battery pack.
Control Functions: Offers proportional forward and reverse electronic speed braking functions.