After stopping by Curts Discount Shooting Supply, while in the Oregon recently, I made the mistake of looking through a TA31F. Drooling after looking through the glass, I felt a sharp twinge slightly below the sciatic region. Then I passed the optic to my wife. She was impressed as well. She took the bait!! After a lot of research back home, into the different models, I decided to try one. My timing was perfect. Trijicon offered a $150 (pre-paid card) rebate while I was looking at them at Optics Planet. I researched the lowest possible price at an authorized dealer, and took the plunge. I purchased the TA11F 3.5x35 w/red chevron. Given the tracking, I'll be signing for it on 10/12/17. While waiting for it to arrive, I researched the availability and differences of mounts. There were several options. I found a NIB A.R.M.S #19LD (2.9oz) for $39. Yes, it's authentic. I ordered one. I also found a GDI R-COM E-Model (4.1oz) for $40. Again, NIB and authentic. I picked up one of these as well.