RadioMaster ER4 2.4GHz ELRS 4CH PWM Receiver with Voltage Telemetry

Product description RadioMaster ER4 2.4GHz ELRS 4CH PWM Receiver The RadioMaster ER4 is an ultra-lightweight 2.4GHz ExpressLRS (ELRS) PWM receiver designed for RC airplanes, small aircraft, boats, cars and other radio-controlled models. Weighing just 3 grams, it provides four direct PWM outputs in a compact package, making it suitable for lightweight builds where space and weight matter. With automatic voltage telemetry, Wi-Fi firmware updates and WebUI configuration, the ER4 offers convenient setup and useful monitoring features for compatible ExpressLRS radio systems. Key Features 2.4GHz ExpressLRS wireless protocol Four PWM output channels for direct servo connections Ultra-lightweight design weighing approximately 3g 15cm high-sensitivity antenna Automatic telemetry of receiver supply voltage or external battery voltage Wi-Fi firmware updates and WebUI configuration CRSF/SBUS serial output support Compatible with 2.4GHz ExpressLRS transmitters and modules Technical Specifications Brand: RadioMaster Model: ER4 Frequency: 2.4GHz Protocol: ExpressLRS (ELRS) Output: 4-channel PWM Serial output: CRSF/SBUS Operating voltage: DC 4.5–8.4V Telemetry power: 10mW, as listed in RadioMaster's product specifications External battery voltage detection: DC 4–35V Antenna: 15cm high-sensitivity antenna Dimensions: 30 × 15 × 5mm Weight: Approximately 3g Pre-installed firmware: ExpressLRS 3.3.0, according to the manufacturer's listing Package Includes 1 × RadioMaster ER4 2.4GHz ELRS PWM receiver 2 × Heat-shrink tubes 1 × Type-A voltage telemetry wire 1 × User card Compatibility note: Requires a compatible 2.4GHz ExpressLRS transmitter or external module. Check the transmitter's ELRS firmware and binding configuration before use.