What is the return policy?

Most unopened items in new condition and returned within 90 days will receive a refund or exchange. Some items have a modified return policy noted on the receipt or packing slip. Items that are opened or damaged or do not have a receipt may be denied a refund or exchange. Items purchased online or in-store may be returned to any store. Online purchases may be returned via a major parcel carrier. Click here to initiate a return.

How energy-efficient is the Grow Spectra LED VR 440-440W?

The Grow Spectra LED VR 440-440W is highly energy-efficient, consuming only 440W of power while delivering optimal light conditions for plant growth.

What is the coverage area of the Grow Spectra LED VR 440-440W?

The exact coverage area can vary based on the height at which the light is hung and the growth stage of the plants. However, it's designed to cover a significant area, making it suitable for commercial growing operations.

Is the Grow Spectra LED VR 440-440W waterproof?

While the Grow Spectra LED VR 440-440W is designed to be durable and can handle humid environments, it's essential to refer to the product's specifications or contact the manufacturer for detailed information on its water resistance.

How long is the lifespan of the Grow Spectra LED VR 440-440W?

The Grow Spectra LED VR 440-440W is built for longevity, typically lasting for several years with regular use. The exact lifespan can vary based on usage and environmental factors.

Is there a warranty for this product?

Please check the warranty tab on this page for warranty information.

How long will shipping take?

Please check our shipping policy here for shipping information.

What is the return policy?

Please check our return policy here for return policy information.

Mammoth M400 Spectral PAR Meter – Scientific Precision in the Palm of Your Hand

The Mammoth M400 PAR Meter & Spectrometer is a next-gen light analysis tool built for growers, researchers, and engineers demanding ultra-accurate spectral data. With a high-speed processor, 2nm resolution, and CCD optical sensor, it measures PAR, spectrum, color temperature, chromaticity, irradiance, and more. Lightweight, touchscreen-operated, and export-capable—this powerhouse outperforms $500+ units at a fraction of the price.

Features & Benefits
Product Specifications
What is included?
Warranty Policy

Mammoth PAR Meter & Spectrometer – Dial In Your Grow Like a Pro

The Mammoth PAR Meter & Spectrometer is your all-in-one tool for measuring light intensity, spectrum output, and environmental accuracy. With precise PAR readings and full-spectrum analysis, this device helps growers fine-tune lighting for maximum plant performance. Compact, user-friendly, and highly accurate, it's essential for serious cultivators who want full control over their grow environment.

Delivers precise PAR and full-spectrum analysis—essential for dialing in grow lighting for plant health.
Features 2nm optical resolution and ±0.5nm wavelength accuracy for unparalleled data clarity.
3.5" IPS touchscreen provides real-time spectral graphs and intuitive navigation.
Built with a high-speed CPU and CCD optical sensor for ultra-fast, stable measurements.

Why the Mammoth M400 PAR Meter & Spectrometer Stands Out

Engineered for professionals, the Mammoth M400 delivers lab-grade accuracy in a portable design. With full-spectrum analysis, high-speed performance, and a vivid touchscreen interface, it simplifies complex data into actionable insights. Whether you’re optimizing grow lights or conducting advanced research, this device brings unmatched precision to your fingertips—at a value that beats bulky $500+ units.

Why Choose Mammoth Lighting

At Mammoth Lighting, we're cultivators and innovators. Designed by growers, for growers, our lights are engineered to deliver maximum yield, potency, and efficiency in real-world grow environments. We don’t follow trends—we pioneer them, with proprietary spectrums, exclusive diode blends, and modular designs built to outperform and outlast. Whether you’re scaling a commercial facility or dialing in your boutique craft grow, Mammoth helps you grow smarter, harvest bigger, and stay ahead of the game.

Why Buy From Us?

At GreenThumbDepot, you're not just another sale to a faceless corporation. You're partnering with a team genuinely invested in your success. Our legendary customer service, combined with a promise of unbeatable prices, sets us apart. We're here for you, always.

Excellent 4.8 out of 5 based on 1,247 reviews

If I could rate 6 stars I would!
If I could rate 6 stars I would! My representative Edouard B. has been shockingly responsive! Like - oh my god - an actual SERVICE oriented company. He's dug into my odd connectivity issues I've been having - and following up in an AMAZINGLY timey manner. No shit. You'll be impressed! (And the price was also unbeatable, quick shipping...it's all PERFECT). Thank you Ed!!

Customer service was outstanding great…
Customer service was outstanding great people to deal with they understand your needs and they will do their best to fulfill them there is no way I can complain about them because they are the best help out there.Thanks green thumb depot. I'll definitely order from them again

The machine is doing just what my…
The machine is doing just what my salesman told it would do (I appreciate you Ed thank you) . The machine is what we need for our new business we're starting up, soon to be llc and licensed. We are getting a lot of clients wanting our services. Ed I will be needing more of your products, thank you again.

Fantastic
Great prices, fantastic customer service, and mind blowing shipping! Incredible. Will be using again and telling anyone in need.

FAQ Section

What does the Mammoth M400 measure?

It measures PAR (PPFD), spectral distribution, color temperature, chromaticity, illuminance, irradiance, and more—all with high accuracy.

Is it compatible with grow lights from different brands?

Yes, it works with any light source within the 380nm–780nm range, including LED, HID, and fluorescent.

How accurate is the wavelength measurement?

The M400 offers ±0.5nm wavelength accuracy and 2nm optical resolution, ensuring lab-grade spectral data.

Can I export the data to my computer?

Yes, data can be exported via Excel with 1nm interval outputs. The software is in beta and may not work on all systems.

How long does the battery last?

The built-in high-capacity battery supports up to 24 hours of continuous operation on a single charge.

Is this suitable for commercial growers or labs?

Absolutely. It’s ideal for growers, labs, researchers, and lighting engineers who require detailed spectral analysis.

How quickly can it take a reading?

Thanks to its electronic shutter tech, it offers a minimum integration time of just 50 microseconds for fast results.

Specifications

Mammoth M400 PAR Meter & Spectrometer – Advanced Light Measurement Specifications
Wavelength Range	380nm – 780nm
Optical Resolution	2nm
Wavelength Accuracy	±0.5nm
Spectral Sensor	High-precision CCD optical sensor
Display	3.5" IPS capacitive touchscreen
Data Output Interval	1nm interval exportable via Excel
Illuminance Measurement Range	0.1 Lux – 200,000 Lux
Build Material	All-aluminum alloy body for lightweight durability and portability

What’s Included

The Mammoth M400 PAR Meter & Spectrometer is a powerful, portable solution for growers and researchers seeking detailed light analysis across multiple metrics:

M400 Spectral Light Meter – Full-spectrum, handheld device with touchscreen interface and advanced CCD sensor technology
Protective Hard Case – Custom-fit carrying case to safeguard the device during transport and storage
USB Charging Cable – For quick and easy recharging of the internal high-capacity battery
Quick Start Guide – User manual with setup, feature explanations, and basic troubleshooting tips

Warranty Policy

For warranty and return information, click here.

Mammoth Lighting

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Mammoth Lighting Par Meter and Spectrometer (Par Meter + Wand)