How to assemble an ARF RC aircraft step by step
A general ARF assembly workflow for many aircraft: dry fit, hinges, servo installation, power setup, CG, control checks and first-flight preparation.
XR4 Gemini Xrossband Dual-Band ExpressLRS Receiver
Prices are intentionally not displayed on the site.
Contact RC-MODEL for current availability, technical fit, compatible accessories and a formal quote.
XR4 Gemini Xrossband Dual-Band ExpressLRS Receiver is a RadioMaster product intended for RC aircraft, FPV, surface and telemetry receiver installations. This page presents the practical buying information in one place: compatibility, SKU, variants, radio protocol, use case and technical details.
The content is written for customer decision-making through RC-MODEL, without supplier prices or outbound purchase routes.
Key Advantages
- Organized for RC aircraft, FPV, surface and telemetry receiver installations.
- Part of the RadioMaster receiver range.
- RF/protocol context: ExpressLRS / ELRS, Gemini Xrossband, 2.4GHz, 915MHz / 868MHz.
- Compatibility note: ExpressLRS 2.
- Multiple variants are documented for easier matching to the required setup.
- Includes local product imagery and structured specifications for customer comparison.
Core Specifications
- Product Code: HP0157.XR4
- Product Family: RadioMaster receiver range
- Protocol / RF: ExpressLRS / ELRS, Gemini Xrossband, 2.4GHz, 915MHz / 868MHz
- Compatibility: ExpressLRS 2
- Available Variants: FCC; LBT
- Weight: 1.7g (without antenna)
- Item: XR4 Gemini Xrossband Dual-Band Receiver
- MCU: ESP32D4
- RF Chip: LR1121 x 2
- RF connector: IPEX-1 X 2
- Antenna: Dual-Band T Antenna x 2 (Included)
- Frequency Range: 2.4GHz / Sub-G 900MHz
- Telemetry Power: 100mw
Relevant RC Academy guides
Learn before you buy
These guides explain the setup, safety checks and accessory choices that usually matter for this product type.
Servo selection: torque, speed, gears and voltage
How to select servos for trainers, sport aircraft, large models, cars and boats without under-sizing a control surface.
How to balance an RC aircraft and find the correct CG
One of the most important setup guides: find the CG, install the flight battery, balance the aircraft and avoid nose-heavy or tail-heavy surprises.
Mandatory pre-flight checks for safer RC flying
A repeatable inspection routine for control direction, radio range, failsafe, battery, fasteners, propeller, CG and field readiness.
How to perform the first test flight of an RC aircraft
Ground checks, takeoff planning, trim passes, battery timing and first landing strategy for a new or repaired RC aircraft.
| Technical Specifications | |
| Manufacturer | RadioMaster |
| Brand | RadioMaster |
| Product Code | HP0157.XR4 |
| All Variant SKUs | HP0157.XR4, HP0157.XR4-LBT |
| Available Variants | FCC; LBT |
| Product Type | Receiver |
| RadioMaster Collections | Dual-Band ExpressLRS Receivers, ELRS Receivers |
| Product Family | RadioMaster receiver range |
| Application | RC aircraft, FPV, surface and telemetry receiver installations |
| Item | XR4 Gemini Xrossband Dual-Band Receiver |
| Weight | 1.7g (without antenna) |
| Compatibility | ExpressLRS 2 |
| Protocol / RF | ExpressLRS / ELRS, Gemini Xrossband, 2.4GHz, 915MHz / 868MHz |
| Antenna | Dual-Band T Antenna x 2 (Included) |
| MCU | ESP32D4 |
| RF Chip | LR1121 x 2 |
| Frequency Range | 2.4GHz / Sub-G 900MHz |
| FW Target | RadioMaster XR4 2.4/900 Gemini RX |
| Working voltage | DC 4.5 - 8.4V |
| Maximum receive refresh rate | DK500Hz / K1000Hz |
| Minimum receiver refresh rate | 50Hz |
| Dimension | 22mm * 18mm * 4mm |
| Firmware Version | ExpressLRS v3.5.1 pre-installed |
| Telemetry Power | 100mw |
| RF connector | IPEX-1 X 2 |
| Bus interface 1 | CRSF |
| Bus interface 2 | UART |
Tags: RadioMaster, HP0157.XR4, Dual-Band ExpressLRS Receivers, ExpressLRS Receivers, Receiver, RC radio