Originally Posted By: M_a_x
Itīs not as comfortable as it may seem. They create hot sparks easily but many of them donīt tend to spray them on your tinder in regular use. It may take some training and adjusting to make them do that. So try before you need it. Remember that they are designed to keep the sparks in the gas flow.
I have one of the flints (glued in a small PVC pipe as handle) and a Swiss + Tech Utili Key on my key ring. It works well. The size is suitable for a PSK. A training sample of the flint lasted for about 50 ignitions by now and is still good for more.
It may be possible to cut away part of the metal cup of the striker with a cutting wheel to allow the sparks to be directed to your tinder. The purpose of the cup is to contain the sparks, open up the cup and it will not contain them so well. the trick is to know where to open the metal cup to reliably get sparks into your tinder.