I ve been using this almost daily for about a month now. Lights on first or sometimes the second try every time! Very pleased with this insert and will get another for one of my other Zippos.
This insert worked fine, usually lighting on the second flick. HOWEVER, the gas reservoir is way too small. Even with the flame set low, the most you can get is 4 or 5 cigars lit before you have to refill.
I've had it for about 3 weeks, and I wasn't expecting that it would still be working. It's not a first time every time, more like a second time every time lighter, but every one who see's me light a cigar with a zippo thinks I'm crazy until they see the torch. I love it and would buy ten more.
I purchased two Thunderbirds as I have a pair of WWII Zippos. One has never worked and the other is constantly clogging and frankly a pain in the butt. I just got a Xixar for about $20 and it is far and away a better lighter and guaranteed for life.