I won't write a long review as there are others for this watch online, mostly for the wrist version.

This clip on version is ideal.  It is precisely 2.74 ounces.  The width is 2 inches.  The body length is 2.5 inches.  The total length including clip is 4.5 inches.  It used Cr2032 battery.

I cannot imagine wearing this on a wrist unless one is Shaquille O'Neill.

I enjoy that, as in the photos, the carabiner flips like a stand so that this can rest on a table.  That cannot be done with the wrist models.

Avid fitness walker and hiker, and I clip on my belt loop and use it daily.  I do lap times and splits, and it's nice to know temperatures.  It's not hard to use, and takes 10 minutes to set up and less than 30 minutes to fully understand.  I find the compass, after a simply 4 minute calibration in the instructions, dead on accurate.

When I workout, I like that it is down at my waist, rather than on my wrist--it's easier to use and access there.  I wish the readout was changeable for direction, because if you hang it on a backpack, the reading is upside down.  They should allow the user to select direction.

It's readable even for so-so vision, and the Indiglo works well.  The alarm is rather quiet, and it may or may not wake you up.  It certainly is pleasant to hear, and the hourly chime is not offensive.

Every couple of years I stumble upon a product that is so ideal, so well constructed, and so worth the price (even though this is expensive, it is quality built) that I buy a second one.  Always afraid the company will either stop making them (as Timex did with the Helix line), or "improve" them in some meaningless way (e.g make it smaller, which would be harder to read and undesirable if used with a 'biner).  This is one of those watershed products.  I'm buying a second one.