This is a entrance hole from a Tekan II by G5. It is the only head I have shot out of my Vortex, flew great and did not need to try another. This head did fine and has been able to satisfy my mechanical B-Head itch I have had for several years. Would like to play with some Fixed blades and when I do The G5 Montech's will be first and then the slicks next. G5 and Slicks next because I dislike heads with aluminum in them. Good luck and let us know what you get and how it works.