Convoy M21B SST40 flashlight review

Luminus SST40 LED
2300 lm output
40000 cd intensity
1 x 21700 Li-Ion battery

The Convoy M21B SST40 flashlight was released in 2019. It uses Luminus SST40 LED, SMO reflector and 1 x 21700 Li-Ion battery. The powerful emitter in this flashlight provides up to 2300 lm output, 40000 cd intensity, and a beam distance of 400 m.

Curious to know if this Convoy flashlight is top-notch? Stay tuned for the answer!

Table of Contents

  • Convoy M21B SST40 specifications
    • Body, materials, weight, colors
    • System, LED, lens, reflector
    • Performance, flux, intensity, throw
    • Software, user interface, modes
    • Features, battery, protections
    • Accessories, package contents
  • Conclusion, pros and cons
  • Photos
  • Comparisons

The content of this article reflects our own experiences and viewpoints. We aim to offer insights on a topic, and we hope others find it helpful and motivating. Additionally, we make every effort to provide accurate and comprehensive coverage.

Convoy M21B SST40 / M21BS

The flashlight is a must-have tool for outdoor activities, it offers guidance and safety. This light has 4 modes of lighting. The M21B SST40's mode memory makes the user experience more seamless and intuitive.

Convoy M21B SST40 specifications

NameM21B SST40
Rated 4 / 5 based on 1539 user votes.

Flashlights let you navigate in the dark. They help you find supplies and signal for help.

Convoy M21B SST40 / 5

Body, materials, weight, colors

Weight120 g
Length141.5 mm
Body diameter27.1 mm
Head diameter35.7 mm
Materialaluminium alloy with HAIII hard-anodized finish

This 120 g flashlight is slightly heavier than most handheld flashlights. The best flashlight size depends on personal preference. The aluminium body of the M21B SST40 has a reputation for being durable and strong. The HAIII coating is often matte or textured. This flashlight features a captivating black color.

Convoy M21B SST40 / 1

System, LED, lens, reflector

EmitterLuminus SST40 LED
Color temperature6500 K / 5000 K
LensAR coated glass
Switchmechanical rear, forward clicky

Luminus is a US-based LED manufacturer. In the lighting industry, it has gained recognition as reputable. Color temperature is used to quantify the color appearance of light sources. Flashlights use the smooth reflector when long-range light is important. The AR coating on the lens maximizes light transmission. The M21B SST40 uses multiple switches. They allow for one-handed operation. Mechanical switches offer tactile feedback. Users can feel a distinct click or resistance when they press the switch. A simple press or click of the rear switch turns the flashlight on or off.

Convoy M21B SST40 / 2

Performance, flux, intensity, throw

Flux2300 lm
Intensity40000 cd
Throw400 m
CD/LM factor17.39

The 2300 lm output of M21B SST40 provides great flexibility. The M21B SST40 flashlight has 40000 cd, it can light objects at greater distances. The throw distance is the farthest distance the flashlight can light an object. The cd/lm factor is the candela-to-lumen ratio. It shows how concentrated a light source's output is.

Convoy M21B SST40 / 3

Software, user interface, modes

Modes4 modes
Mode memoryyes
Ramping modeno

A flashlight's modes are different output settings or brightness levels. The flashlight has mode memory. It remembers the mode you were using when the light was last turned off.

Convoy M21B SST40 / 4

Features, battery, protections

Battery1 x 21700 Li-Ion battery
Battery indicatorno
Charger portno
Thermal regulationyes

The Convoy M21B SST40 flashlight is powered by 1 x 21700 Li-Ion battery. The M21B SST40 doesn't have charger port. The Low Voltage Protection helps save the battery's capacity. The thermal protection feature helps prevent overheating. The "7" in the IPx7 rating shows that the flashlight can survive being submerged in water.

Accessories, package contents

Package contentslanyard

The lanyard of the M21B SST40 protects the flashlight from accidental damage.

Conclusion, pros and cons

This Convoy flashlight, like any other, has its strengths and weaknesses. Let's take a close look at both sides to understand this flashlight better. I share my thoughts on its standout features and the parts that might need improvement. Keep in mind, these are just my opinions, and you might have a different perspective.


  • lightweight
  • aluminium body
  • AR coated lens
  • tactical switch
  • super bright
  • multiple modes
  • mode memory
  • low-voltage protection
  • thermal regulation
  • waterproof


  • cool light
  • no battery indicator
  • no built-in charger
  • no auxiliary LEDs
  • non-magnetic


Convoy M21B SST40 / M21BS photo 1.
Convoy M21B SST40 / M21BS photo 2.
Convoy M21B SST40 / M21BS photo 3.
Convoy M21B SST40 / M21BS photo 4.
Convoy M21B SST40 / M21BS photo 5.
Convoy M21B SST40 / M21BS photo 6.
Convoy M21B SST40 / M21BS


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Updated: April 23, 2024

David Hagon
I love bushcraft and flashlights. I find joy in mastering wilderness survival skills and exploring the realm of illuminating gadgets. Bushcraft isn't just fun, it's a learning journey. I form a strong bond with nature. It's more than a hobby, it enriches me in practical and spiritual ways.