This is a one-of-a-kind, handmade by Master Brusso and was used to develop weapons retention. This deeper finger-holding area was a significant innovation and worked very well. We call this a Gen 1 tool as it is handmade. It went into months of testing too. It will come with a certificate of authenticity for all your collectors out there. Great Xmas gift for the person with everything or wants something no one else has.