Master Martin introduced this tool to Master Peter Brusso in 2003. Master Brusso liked the idea but not the design so asked his teacher for the right to develop this idea but with an engineers mind into it. Master Martin gave him his OK and then our product line was invented. So this is a one of kind self defense tool and will come with a certificate of authenticity which we will email to you after purchase. You can then print out the certificate for your wall or records. It has the word “Defender” written on it so that stays as it was since 2003. First come first serve!