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Model 855-858
Wolo® Express Pro™
12-Volt 128 Decibels 308/337/366 Hz

Model 855-858 Wolo® Express Pro™  12-Volt 128 Decibels 308/337/366 Hz

Availability: In stock

Price: $273.99

Model 855-858 Wolo® Express Pro™  12-Volt 128 Decibels 308/337/366 Hz


Wolo, the first company to design and sell ABS train horns, has a new universal flat rack design that makes installation easier because the horn requires less mounting space than other styles of train horns. The WOLO EXPRESS PRO has three black trumpets that are made of reinforced ABS plastic, producing a sound that is just plain outrageous! The trumpets can be separated from the mounting base, for installation’s that have limited space. Built rugged with a heavy-duty steel-mounting base that has a powder coat black finish, designed to withstand the toughest roads and vibration. WOLO EXPRESS PRO comes with a built-in heavy-duty 12-volt electric solenoid. 

The on-board air system provided is designed to produce a large volume of high-pressure air to power the WOLO EXPRESS PRP TRAIN HORN and includes everything necessary for a professional installation. The compressor has a heavy-duty 12-volt motor that is balanced to precision. There are 4 heavy rubber bushings mounted into the compressor base plate to virtually eliminate vibration. For surface mounting of the compressor, there is an extended length stainless steel high pressure hose that connects the compressor to the 2.5-gallon metal air storage tank. Other features of the WOLO EXPRESS PRO include; a tank that has a built-in pressure switch, manual water drain, pressure gauge, pressure relief valve and brass fittings. Kit also comes with mounting hardware, 10 ft. of flexible high-pressure hose and 20 ft. coiled filler hose with quality brass fittings.

Additional Information

Installation Details

Model 855-858 Wolo Express Pro Horn Installations PDF (English)

Model 855-858 Wolo Express Pro On-Board Air System Installations PDF (English)


128 Decibels
308/337/366 Hz – Low Range
Horn size: L 19 in. x W 18 in. x H 9-1/2 in.
Horn output with 90/110 psi: 128 db
Horn construction: ABS plastic, base - painted enamel, trumpets – semi gloss black finish
Electric solenoid: 12 volts / 300 milliamps
Hose type: 1/4 in. O.D.
Air fittings: Brass
Mounting hardware and 10 ft. of 1/4" O.D. high pressure hose included.

Voltage: 12-volts
Current: 21-amps at peak
Duty-cycle: 33% @ 100 psi
CFM: 2.55
Pump has washable air filter
Oil-less maintenance free
Permanent magnet motor that is gearless with
thermo protection
Compressor size: L 10-1/4 in. x W 3-1/2 in. x H 6-1/2 in.

Tank capacity: 2.5 gallons
Built in pressure switch: On 80 /off 110 psi
Safety pressure relief valve
Pressure gauge
Fitting size: All brass
Petcock water drain
Tank size: L 17-1/4 in. x W 6-1/2 in. x H 8-1/4 in.
Size compressor mount on tank:
L 17-1/4 in. x W 6-1/2 in. x H 15-1/2 in.


Replacement Parts No
Sound Options No