I have recently been asked about the darts in the picture of the Hat Trick a few posts back. They are my 23 gram Warriors by Shooter's Edge. They are fixed point darts and I have never seen anything like them. The shaft they take is the top portion of the "Spinster Aluminum" shafts. It took a little while to learn how to throw them properly as the gripping is also different. The dip in the middle appears to be a finger placement but I do not use it as such (as I rarely, if ever, place a finger on the point when throwing). There are a few other designs and weights in this dart but this was the only one I could find when I discovered their existence and sought them out.
As always, click the image for a larger picture.