Product review (5 stars): Fixed a flaky gas fireplace insert!
I am unreasonably excited about this thing.  We just bought a house with a gas fireplace - not a clue what make, model, year, etc.  The fireplace would light and run for a few minutes at a time, then *POOF* - it went out - pilot light too.  I could re-light the pilot and try again - and it would work for a few minutes, then, well, you get the idea.

Quick Googling indicated a faulty thermocouple could cause this problem, so I bought this one, sold on the word "Universal".  Lo and behold, it was an EXACT replacement for the old one - fits my Dontknowthebrand Somerandommodel XL fireplace insert perfectly.  And the fireplace has worked perfectly since.  So if you're the owner of a Somerandommodel XL, buy with confidence!