Train Horn Compatible with Ryobi ONE+ 18V Battery

A complete device for your ONE+ battery

The battery connects to a horn that already contains its compressor, handle and trigger. You do not need to supply a drill, run wires through a vehicle or install a separate air system.

The trumpets ship separately from the base. Thread them into place by hand, connect a compatible Ryobi ONE+ 18V battery, and use the trigger or remote. The Quick Start Guide is included to help you get familiar with the controls.

Choose the trumpet layout, keep the same simple operation

The model selector changes the horn configuration, price and product photographs. The battery platform and essential operating method stay the same across this Ryobi-compatible range.

Dual models have two selectable volume levels. Models with four or five trumpets have three. The standard remote is included with each horn and operates at up to 300 ft; a separate long-range option is rated up to 2,000 ft. Real-world radio range varies with the environment.

Built for the horn, rather than adapted around it

We developed a dedicated housing to fit the air-compressor motor securely instead of repurposing a complete power tool. This improves component placement and avoids dismantling donor tools for their shells.

Boss Horn’s current housing arrived in mid-2026, following the custom control board released in mid-2025. The metal-alloy trumpets are powder coated for long-lasting use and resistance to corrosion, replacing the less durable plastic approach used in early devices in this category.

Protection while you use it

Battery voltage is checked when the motor starts and while it runs. Low voltage prevents the motor from continuing to take power from a depleted pack. This protection is controlled by the horn electronics.

The board also manages motor heating by tracking operating time. A cooling lockout pauses use when necessary. Allow roughly 10 minutes with the battery connected; if the battery was removed during lockout, reconnect it and wait 10–15 minutes for the cooling timer to finish.

Protection when the remote is waiting

The radio receiver has Always on, Always off and Standard modes. Standard mode powers reception for three hours after connection or the most recent horn activation, then shuts the receiver down automatically.

Boss Horn’s connected-storage testing showed protection against deep-discharge damage over months, and in some conditions for more than a year. Removing the battery remains the recommended storage practice because it prevents unintended activation, even though the electronics manage discharge.

Included essentials, optional power accessories

Each horn includes a standard remote, Quick Start Guide and 1-year warranty, and is assembled in the USA. A compatible ONE+ 18V battery and charger are required separately.

If you already own compatible power accessories, you can use them. Otherwise, choose the optional battery and charger before placing your order.

Handheld control or remote operation

• Built-in trigger: press the trigger on the horn handle to activate it.
• Included wireless remote: up to 300 ft range.
• Optional long-range remote: up to 2,000 ft range, sold separately.

Radio range depends on obstacles, interference and the surrounding environment.

Selectable volume

Choose among the volume settings available on your ONE+-compatible model before use. Dual and multi-trumpet configurations have different numbers of levels.

Your selected model: 3 volume levels. Two-trumpet models have two levels; four- and five-trumpet models have three.

Let the cooling timer finish

The electronics manage motor heating by monitoring how long it runs. If a lockout interrupts operation, give the horn time to complete its cooling interval.

1. Leave the battery connected. Allow about 10 minutes before continuing.
2. If you removed the battery during lockout, reconnect it. Wait 10–15 minutes for the cooling timer to finish, even if the motor has already cooled.

Battery protection at startup and in standby

A depleted ONE+ pack should not keep powering the motor. The horn also manages receiver standby to address the slower drain that can occur between activations.

• Motor voltage checks: the board checks battery voltage at startup and during operation. Low voltage prevents the motor from draining a depleted pack further.
• Receiver power management: radio standby power is controlled separately to reduce the drain associated with leaving a receiver on continuously.

Choose the receiver power mode

Always on

The wireless receiver stays powered.

Always off

The wireless receiver is switched off.

Standard

The receiver stays active for three hours after connecting the battery or sounding the horn. Every activation starts a new three-hour window; after it expires, the receiver switches off automatically.

After use: disconnect the battery before storage to help prevent unintended activation from radio signals.