These do work and get the job done. I’ve dealt with many different brands and types of fire starters and these are definitely far from the bottom of the list.
I have however found better products since this. The design of the starters are a little weird in my opinion since they are like little half spheres and you are suppose to put them upside down, but they tip and just seems to not burn as well as it could. Overall not a bad fire starter, however I do believe it’s not that hard to find a better one with a more convenient design.