R21 3000m Long Range 4-Button RF Remote Transmitter

Reliable long-range control for industrial and outdoor projects

The R21 is a high-power 4-button RF remote transmitter designed for projects that need dependable wireless control over long distances. It is suitable for motor control, electric gates, pumps, lighting systems, lifting equipment, access control and other remote switching applications where stable signal transmission is more important than decorative consumer features.

With a rated open-space transmission distance of up to 3000 meters, the R21 gives installers and equipment builders a practical option for farms, warehouses, workshops, factories, construction sites and large outdoor areas. Actual working distance may vary depending on receiver sensitivity, antenna design, installation height, surrounding buildings and electromagnetic interference.

Flexible frequency and coding support

The transmitter supports common 315MHz and 433MHz RF systems, making it easy to match with many receiver modules and relay control boards. It is compatible with both learning-code and fixed-code applications, including EV1527 and HS2260 coding chip platforms.

- 315MHz / 433MHz frequency options for different markets and receiver requirements

- Learning-code and fixed-code compatibility for flexible pairing

- ASK modulation for straightforward integration with standard RF receiver circuits

- 4-button layout for multi-function or multi-channel control

Strong transmission performance

Powered by a DC9V battery, the R21 is built for stronger transmission output than compact key-fob remotes. The transmitter is specified with more than 1.5W transmitting power and an operating current of approximately 120-160mA, helping it maintain signal strength across longer operating ranges.

The 4-button design can be used for separate channels, direction control, start/stop commands, mode switching or customized functions depending on the paired receiver and control logic.

Durable hand-held construction

The housing combines plastic and metal materials to provide a practical balance of portability, grip comfort and field durability. The compact form factor is easy to carry, while the clear button layout helps operators trigger commands quickly in daily use.

This model is especially useful when the operator needs to stand away from machinery, control equipment across an open yard, or operate a receiver installed in a location that is not convenient to access directly.

Typical applications

- Gate, door, shutter and barrier control systems

- Water pumps, farm equipment and greenhouse control

- Lighting, warning lights and remote relay switching

- Electric hoists, winches and lifting equipment

- Industrial receiver kits and customized control panels

- Long-distance wireless control for workshops, warehouses and outdoor sites

Integration notes

For best performance, pair the R21 with a receiver that matches the selected frequency and coding type. Long-distance operation depends heavily on receiver antenna placement, installation height and line-of-sight conditions. Where the environment includes metal structures, walls, high-voltage equipment or heavy RF interference, testing the complete transmitter-and-receiver set on site is recommended before final installation.

Rivers can support matched transmitter and receiver combinations for OEM projects, replacement applications and customized wireless control systems. Share the required control distance, working voltage, channel count and installation environment so the appropriate receiver and antenna configuration can be selected.

Key advantages

- Up to 3000m open-space transmission distance

- 4-button control for flexible command layouts

- 315MHz and 433MHz compatibility

- Supports learning-code and fixed-code systems

- EV1527 / HS2260 encoding compatibility

- DC9V battery-powered transmitter with strong RF output

- Suitable for industrial, agricultural, access control and outdoor wireless control projects