O4 Mini Task Light

O4 Mini Task Light, retail $TBA (http://www.cmgequipment.com)
Manufactured by CMG Equipment (http://www.cmgequipment.com)
Last updated: 12-24-03

LED Light

The CMG O4 is a super bright keychain light with a futuristic shape, rubber grips, and a simple but effective switching mechanism.
The high brightness LED is powered by a single CR2032 or a pair of CR2016 lithium coin cells (depending on LED color), and the unit is water-resistant because it has no external switch to leak.

The O4 is a good looking light, so you need not be ashamed to carry it around on a zipper, keychain, bag handle, etc.


The O4 is ready to go right out of the pack. To get a momentary burst of light, just give it a squeeze. If you wish for it to stay lit continuously, swing the small metal lever on the top of the light downwards so the end of it covers the rubber button. This lever applies enough pressure on the button to light the LED without having to keep squeezing. Swing the lever back to the top position to turn the O4 off.

To change the batteries, remove the phillips screw from the back of the O4, and use a flatbladed screwdriver to carefully pry the two halves apart. Be careful so you don't damage the rubber gasket that seals out the weather.

Remove the old batteries, and insert the new ones, button side (-) facing towards the little circular thing with the LED on it. Reassemble by aligning the two flashlight halves and firmly squeezing together; install the screw and tighten gently but firmly.

This diagram should help clarify things. The batteries are directly under that circular brown thing in the 3rd frame. Just dump them out (you may need to lift out the lower one with your screwdriver or a good fingernail) and install new ones the same way. Flat (+) side down towards the small bottom disc, button (-) side facing up toward the larger disc with the LED on it.

changing batteries

The O4 is a durable little light that also has a measure of water resistance as an added bonus.

When I ran over it with my Rascal scooter, the light came on when the tire was over it, and went back out when the pressure was relieved. However, upon retrieving the light, the lever switch no longer functioned. It still squeezes on and off, but squeezing requires slightly more pressure than before. If you value the ability to operate the light in hands-free mode, you probably don't want to step on it or run over it with the riding mower unless you happen to have a screwdriver in your pocket.

A failure analysis I conducted revealed the true cause: it wasn't the flashlight at all; it was the batteries that warped slightly under the pressure. Simply swapping the cells; placing the top cell on the bottom, was enough to restore proper operation. Replacing them with new batteries will also restore operation, but as I found that was unnecessary.

12,800 peak mcd blue, 22,400 peak mcd white

Although I've had these things for awhile, I never did get around to testing them. The poor things have been largely ignored, but now their turn in the spotlight has come. I will be using one as a daily carry item, and keeping the other one in relative comfort as a control sample.

UPDATE 12-24-03:
I've found out that the CMG O4 will now be sold as a momentary-only light, without the spring steel clip for constant-on.

Any updates related to this review will be posted as they happen.

Small and discrete package
Nice looking flashlight
Durable construction
Waterproof (not just splash resistant)
Offers continuous-on with an innovative switch

Tools needed for battery change

        MANUFACTURER: CMG Equipment
        PRODUCT TYPE: Miniature keychain flashlight
        LAMP TYPE: 5mm LED, choice of colors
        No. OF LAMPS: 1
        BEAM TYPE: Varies by LED color
        SWITCH TYPE: Squeeze momentary and pivoting external lever
        BEZEL: None
        BATTERY: 1 CR2032 or 2 CR2016 lithium coin
        CURRENT CONSUMPTION: Estimated to peak at 60mA
        ACCESSORIES: Split ring



Do you manufacture or sell an LED flashlight, task light, utility light, or module of some kind? Want to see it tested by a real person, under real working conditions? Do you then want to see how your light did? If you have a sample available for this type of real-world, real-time testing, please contact me at ledmuseum@gmail.com.

Please visit this web page for contact information.

Unsolicited flashlights appearing in the mail are welcome, and it will automatically be assumed that you sent it in order to have it tested and evaluated for this site.
Be sure to include contact info or your company website's URL so visitors here will know where to purchase your product.

WHITE 5500-6500K InGaN+phosphor 
ULTRAVIOLET 370-390nm GaN 
BLUE 430nm GaN+SiC
BLUE 450 and 473nm InGaN
BLUE Silicon Carbide
TURQUOISE 495-505nm InGaN
GREEN 525nm InGaN 
YELLOW-GREEN 555-575mn GaAsP & related
YELLOW 585-595nm
AMBER 595-605nm
ORANGE 605-620nm
ORANGISH-RED 620-635nm
RED 640-700nm
INFRARED 700-1300nm
True RGB Full Color LED
Spider (Pirrahna) LEDs
True violet (400-418nm) LEDs
Agilent Barracuda & Prometheus LEDs
Oddball & Miscellaneous LEDs
Programmable RGB LED modules / fixtures
Where to buy these LEDs 
Links to other LED-related websites
The World's First Virtual LED Museum
The Punishment Zone - Where Flashlights Go to Die
Legal horse puckey, etc.
LEDSaurus (on-site LED Mini Mart)

This page is a frame from a website.
If you arrived on this page through an outside link,you can get the "full meal deal" by clicking here.