4Sevens Preon P0 Review

Posted February 24th, 2012 in Links by Rob

I was very excited to receive a package in the mail recently from the folks at 4Sevens. This parcel contained a minuscule light with some interesting and innovative features. Let’s take a look at this new light from 4Sevens.

The first thing you notice about the Preon P0 is how tiny it is. I love small AAA lights, but this light takes it to a whole new level. Here it is beside a Spyderco Dragonfly, one of the smallest knives I own.

I’m not a huge fan of keychain lights because I don’t like having to pull out my keychain just to use my light. I know I’m picky, but I like to carry a light with a clip. If it doesn’t have a clip, I like to carry it in the change pocket of my jeans, but the Preon P0 can easily get lost in the depth of a typical change pocket.

After the size, you notice the unusual green reflector. I know it isn’t intended to be a reflector, but it still ends up reflecting a little and giving the light a slightly green tint, so I’ll call it a reflector. The green is actually glow in the dark material that… wait for it… glows in the dark!

Because the P0 has no true reflector, it has no hotspot. It’s a clean, even, floody circle of light.

Here you see it next to the reflector of a Preon Revo:

Since I brought up the 4Sevens Preon Revo, let’s compare it to the 4Sevens Preon P0.

I used to think the Preon Revo was pretty small before I got the Preon P0. Despite using the same battery and form factor, the P0 makes the Revo look like a giant.

When I first saw the finish and the small size, I immediately assumed that it wouldn’t have much grip for twisting, but it actually has better grip than the Revo. I think it has to do with a combination of factors. The P0 head is slightly longer than the Revo head and gives you more grip area. Also, the P0′s satin finish has noticeably more grip than the glossier Revo head finish. The ridges help to give the Revo head some grip, but my fingers always slide till they hit the ridges and I feel like I have to grip it pretty tight. In the end, the Preon P0 gives a more pleasant head turning experience.

The Preon P0 has some interesting features that the Revo is lacking. Let’s go backwards and look at the tail first.

You will notice that the P0 has the keyring hole on the side and has a flat tail that is suitable for tailstanding. This is something that the Revo lacked, but it gets even better. There is a magnet embedded in the tail.

This magnet allows you to mount the light in some pretty unusual and creative ways. The only limits are your creativity and the amount of steel in the room. ;)

I literally walked around the room trying to attach it to all sorts of things. It’s pretty amazing. Here you can see that I attached it to my microphone arm and turned it into a creative desk lamp.

Here I hung it on a wall light fixture. This would be pretty handy during a power outage.

The magnet also helps to hold the battery securely. It won’t immediately fall out and roll under the refrigerator. You have to give it a shake to break the hold of the magnet.

At the other end of the light, we have the glow in the dark “reflector.” For me, it doesn’t add any real functionality, but it certainly raises the cool factor. If you were looking for the light in the dark and you didn’t have it standing on it’s head, it might help. Unfortunately, the material doesn’t hold a glow/charge for all that long, so you can’t count on it if you want to use it to find your light in a dark drawer or on the nightstand after some time.

So now let’s talk about the important part. How it actually functions. I already mentioned that I like the grip on the head for twisting, but unfortunately, the activation of the light leaves something to be desired. As you get close to the point of contact/activation, you are pressing up against a rubbery gasket in the head.

The washer causes the resistance to increase as you get close to the activation. It gets relatively difficult to twist that last little bit. I also found that when I twisted it to the on position, it occasionally backed off and lost contact. This is particularly annoying when you want to use the higher mode and have to do the double twist again. I have never had this problem with any of the other Preons and it was slightly off-setting.

I have found the low setting to be adequate for walking in areas without streetlamps and for flashing at vehicles to make sure they know you are there.

The high setting gives a noticeable increase of light, but it is still a very spread out beam and doesn’t throw very far.

Here are the specs from 4Sevens:

Preon P0 Specifications

  • Max Output: 25 Out-the-front (OTF) lumens
  • Material: Stainless Steel
  • Lens: Optical-grade glass lens with anti-reflective coating on both sides
  • Water resistance: IPX-8
  • Battery: One AAA, included. Please do not use lithium-ion cells in the Preon P0 as it will destroy the light (see voltage range to select acceptable batteries for this light).
  • Operating voltage range: 1.0V – 1.5V
  • Two Output Modes:

    Low: .24 OTF Lumens, 120 hours
    High: 25 OTF Lumens, 1.5 hours

  • Dimensions:

    Length: 2.2 inches
    Diameter: 0.5 inches
    Weight: 0.46 ounces

Included Accessories

  • Split-ring for keychain attachment
  • One AAA battery


Operating your Preon P0 is simple. Insert the battery with the positive side (+) toward the head. To turn it on, tighten the bezel (head) fully. The Preon P0 will turn on when the bezel is tightened, and turn off when the bezel is loosened. To switch between High and Low output, turn the Preon P0 off and then on again within 1 second. If the Preon P0 is turned off for 2 seconds or longer, it will revert back to Low.

The Preon 0 is listed on the the 4Sevens website for $24.99. At that price, I’d say this nifty little gadget is worth it. Personally, it won’t make it into my EDC rotation, but it’s definitely a fun light. It would make a great gift for someone who would appreciate the more “gadgety” features and wouldn’t expect it to be a hard-use EDC light.

Quick side note about batteries! None of my NIMH rechargeable batteries worked with the Preon 0. I had to use the battery that came with the flashlight. The metal nub on the positive end of the rechargeable batteries is too large to fit through the washer. I probably could have forced it to work, but I definitely don’t recommend it as it could damage the electronics in the head. You can see the difference in the photo below:

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2 Responses so far.

  1. Dan says:

    Nice review Rob! The P0 looks very interesting and I'm glad it looks like 4sevens made another winner.

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