Princeton Tec Impact II Flashlight, retail $TBA (
Manufactured by Princeton Tec (
Last updated 01-15-08

The Princeton Tec Impact II is the baby brother to the original Impact. The Impact II uses four AAA cells, instead of four AA cells. It also comes in a transparent, candy colored case just like the Princeton Tec Attitude.

The Impact II features a single white LED and a special lens built right into the bezel to focus the LED beam. It runs from four included AAA cells, and is waterproof (submersible) to 500 feet, so you never have to worry about it getting wet.


To use the Impact II, first get it out of the package and install its batteries (see below) and it's ready to use.

To turn it on, twist the bezel (head) clockwise until it comes on. Turn the bezel counterclockwise to turn it off.

I found I could turn it on and off with just one hand. This may depend a bit on how well the O-ring is lubricated though; if the head becomes too tight to operate with one hand, you may need to take the head off and clean & lube the O-ring.

To change the batteries in the Impact II, unscrew & remove the bezel, and set it aside. Remove the LED & reflector assembly, and set that aside too. Dump the dead batteries in the cat box - er - garbage can.
Hold the flashlight body so the clip is facing left or right (doesn't matter). Load two of the batteries in one chamber button-end (+) first, and load the other two into the remaining chamber flat-side (-) first.

Now, look at the bottom of the LED/reflector board. You'll see a "+" embossed by one of the shiny metal contacts, and a "-" embossed near the other contact. Be sure the side with the "+" by it goes to the button (+) terminal on the batteries. Lower this piece in place, and screw the bezel assembly back on. If you have the LED assembly in right, the Impact II should come on when the bezel is almost screwed all the way on. Batteries are said to last approximately 75 hours before they need replacing.

The PT Impact II appears to be a tough and durable flashlight. It's great for outdoor use because it's completely water resistant, and can survive fine if it falls into a creek or pond, or even if the dog takes a whiz on it. And if it becomes dirty or muddy (or to get the dog whiz off) just take the hose to it. Won't hurt the Impact II a bit.

The Impact II comes with a pocket clip built into the flashlight's body, and a split ring you can install yourself if desired. The plastic pocket clip looks like it could snap off if you really reefed on it while it's still attached to your clothes, but I think you would need to make a concerted effort to break it. Ordinary usage probably wouldn't do it.

The light output is high for a single LED. It's high though, because a lens built into the flashlight bezel focuses and tightens the LED beam. This means the Impact II can "throw" farther than any other single LED light with no lens in front of it.

A very faint rattling or ticking sound can be heard when the flashlight is shaken. This is probably a platinum catalyst pellet somewhere in the head. This pellet is designed to absorb hydrogen gas from the batteries, and ought to be present in all sealed flashlights. So if you hear a faint ticking or rattling sound in the flashlight head when you shake it, that sound can be ignored.

Beam photograph at 12"
Measures 90,400mcd on a Meterman LM631.

This value is high for a single LED because of the focusing lens built into the flashlight. Without the lens, the Impact II would probably read 10,000 or 15,000mcd tops.

Spectrographic plot
Spectrographic analysis of the LED in this flashlight.
Ocean Optics USB2000 Spectrometer on loan from TWO-CUBED.

ProMetric analysis
Beam cross-sectional analysis.
Image made using the ProMetric System by Radiant Imaging.

Test unit was received in September 2002, not too long before I wound up in the hospital. I apologise for the delay in getting it on this site. I don't even know who sent it anymore. :-p
(If you sent it, please pipe up so your name & URL can go here!)

UPDATE: 08-09-04
I've read no fewer than two reports that the clip on the Impact II has become broken.
For this, I have decided to remove 1/2 of a star from its final rating.
It's still a great flashlight, don't get me wrong here. But the clip can become broken.

Durable, tough housing
Small, pocketable size
Bright, for a single 5mm LED
Uses inexpensive, readily available batteries

Lack of spill light might not be suitable for some users
Clip *could* become broken

    MANUFACTURER: Princeton Tec
    PRODUCT TYPE: Small handheld flashlight
    LAMP TYPE: White LED
    No. OF LAMPS: 1
    BEAM TYPE: Circular, focused with little spill light
    SWITCH TYPE: Twist bezel on/off
    BEZEL: Acrylic lens with LED behind it
    BATTERY: 4x AAA cells
    CURRENT CONSUMPTION: Unknown/unable to measure
    SUBMERSIBLE: Yes, to 500 feet
    ACCESSORIES: 4x AAA cells, split ring
    WARRANTY: Lifetime


    Star Rating

Princeton Tec Impact II *

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