Pierce M10i

The M10 is a beautiful piece on engineering, well-designed and well-machined. It's a dual-output CR123A pocket light, with a narrow and a wide optic available. The M10i comes with both optics.

In the picture above, you can see the bezel on the left, followed by the cooling fins, body, and lanyard groove.

This light can operate at either 400mA or 1000mA, and can accept either of two optics (wide and narrow). To change the output level:

  1. Remove the head.
  2. Find the hole in the threads.
  3. Using a toothpick or tweezers (like those found on an ordinary SAK), reach under the threads through the bottom of the head.
  4. Move a tiny switch to change levels. It should be visible through the hole.
  5. I don't remember which position is high or low, so consult your manual.

To change out the optic:

  1. Remove the head.
  2. Grasp the bezel and threads in old rags, and unscrew.
  3. Let the old optic fall onto a soft cloth. Be careful with the glass window.
  4. Handling it by the edges, pick up the new optic and place it where the old one was.
  5. Screw everything back together.

I personally can't tell the difference between high and low, but I think I could if I could compare the two side by side. Low will last longer and high will make the light quite hot, but you'll get pretty flat output from both.

The optics, however, are a different matter. The narrow optic provides a mostly P1-like beam, with great throw and spill. The wide optic, which I prefer due to the rarity of a good flooder, makes a wide flood similar to that of a diffused Gladius - no hotspot whatsoever.

This is a beautiful, reliable light, and I highly recommend it.