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GENMAX · Inverter generator

GM12500iET

Gasoline + Propane + Natural gas inverter generator with 12,500 peak watts

12,500W running12,500W peak458cc OHVGasoline + Propane + Natural gas
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GENMAX GM12500iET 12500W Tri-Fuel Inverter Generator with CO Shield (2026 Model) - Quiet, 50A Outlet, 2-Wire Auto Start
Official product image: GENMAX

Visual spec gallery

The deciding numbers, made scannable.

01 · Maximum output

12,500W peak

Continuous output12,500W running

Size around running load first, then confirm the peak rating covers the largest startup surge.

02 · Fuel output

Gasoline + Propane + Natural gas

Manufacturer-listed output

12,500W run · 12,500W peak

Alternative-fuel ratings are shown only when GENMAX publishes a fuel-specific figure.

03 · Portability

251.9 Pounds

Unit weight

30.9"L x 22.63"W x 29.33"H

Dimensions

Sound rating

62 dBA

04 · Controls & ownership

Starting

Recoil

CO shutoff

Manufacturer-listed

Parallel

Not listed

Warranty

3 Year

Official product gallery

Every manufacturer view in one place.

GENMAX imagery can include the enclosure, control panel, outlets, dimensions, feature callouts, and included accessories.

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Complete specifications

Manufacturer data, organized for comparison.

Power ratings, features, imagery, manuals, and seller links come from GENMAX’s current U.S. model page. A missing figure is labeled instead of estimated.

Never run a portable generator indoors. Keep it at least 20 feet from occupied buildings with exhaust directed away from doors, windows, and vents. Use a qualified electrician and approved transfer equipment for home connections.

Model overview

12,500 running watts and 12,500 peak watts for home backup and rv power. Confirm exact configuration and included accessories with the seller before purchase.

Fuel-specific output

Manufacturer-listed output
12,500W running / 12,500W peak

Operation & ownership

Engine
458cc OHV
Voltage / frequency
120V / 60 Hz
Runtime
up to 10.4 hours on a 6
Fuel capacity
See manufacturer page
Sound
62 dBA
Starting methods
Recoil
Unit size / weight
30.9"L x 22.63"W x 29.33"H / 251.9 Pounds
Warranty
3 Year

Connections

3

Manufacturer feature details

【Tri-Fuel Power & Flexible Fueling】Switch seamlessly between Gasoline, Propane (LPG), and Natural Gas (NG) with the dedicated fuel selector. The separate LPG Inlet ensures safe connection for alternative fuels, making it ideal for long-term home backup, RV trips, and job sites.
【Clean & Stable Inverter Power】Delivers ≤3% Total Harmonic Distortion (THD) pure sine wave power, safe for sensitive electronics like laptops, phones, and medical equipment. Perfect for modern digital lifestyles.
【High-Capacity Output & Multiple Outlets】Features a powerful 458cc OHV engine and versatile outlets: a 120V/240V 50A (NEMA 14-50R), two 120V outlets (30A & 20A), plus 12V DC and dual USB ports. Easily runs heavy loads like air conditioners, refrigerators, and power tools simultaneously.
【Smart Digital Control & 4-Way Start】Control and monitor via the digital display showing wattage, voltage, frequency, runtime, fuel level, and alerts. Start the generator 4 ways: Electric Start, 2-Wire Auto Start (for home backup),Bluetooth App，and Recoil Backup.
【Ultra-Quiet & Fuel-Efficient Operation】Equipped with Eco-Mode that automatically adjusts engine speed to load, reducing noise to as low as 62 dB(A) at 25% load and extending runtime up to 10.4 hours on a 6.1-gallon tank. Ideal for camping and residential use.
【Comprehensive Protection & Portable Design】Built with full protection against overload, over/under voltage, short circuit, and overheating. Includes a robust frame with wheels and foldable handle for easy transport and storage.
【Safety Features & EPA Certified】Includes a built-in CO sensor for added safety in enclosed spaces and is EPA certified for sale in the USA. Backed by a 3-Year Limited Warranty and ongoing technical support.
Show the full manufacturer specification table
Brand
GENMAX
Total Power Outlets
3
Wattage
12500 watts
Engine Power Maximum
1.25 Kilowatts
Fuel Type
Tri Fuel
Starting Wattage
12500 Watts
Power Source
Fuel Powered
Running Wattage
12500 Watts
Recommended Uses For Product
Camping
UPC
784482491319
Item Weight
251.9 Pounds
Manufacturer
GENMAX
Output Wattage
12500
Part Number
GM12500iET
Special Feature
CO Sensor
Item Weight
252 pounds
Included Components
Spark Plug Socket Wrench (1) Wrench
Item model number
GM12500iET
Product Dimensions
30.9"L x 22.63"W x 29.33"H
Style
GM12500iET
Model Name
GM12500iET
Special Features
CO Sensor
Engine Type
4 Stroke
Batteries Required?
No
Ignition System Type
recoil start
Warranty Description
3 Year

Current seller links

Compare offers from GENMAX-listed retailers.

These destinations are supplied on the official model page. Prices and availability can change.

AMAZONGenerator Superstore

Best-fit uses

  • Home backup
  • RV power
  • Jobsite tools
  • High-demand loads

Standout features

  • 12,500 running / 12,500 peak watts
  • Gasoline + Propane + Natural gas
  • Recoil start
  • CO shutdown system

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Official sources:Model pageAll GENMAX generatorsVerified September 15, 2026