Purchased the Vortex VMX3 Magnifier plus the Swing Mount for VMX3 Magnifier SM-01 (which I believe is made by American Defense Mfg. Model AD-SM-01) -- note that magnifier includes a mount which I didn't use. Optic is very good - very clear and no distortions or imperfections. Overall build seems solid but the rubber covering is thick and may interfere with BUIS. Clear plastic bikini covers are also included. The swing mount is excellent quality and locks into place solidly. The swing mount places the magnifier behind my Aimpoint Micro T1 in perfect co-witness. After three outings (albeit no rough handling) with this setup on my Daniel Defense DDM4 everything seems to be holding up nicely. The magnifier certainly helps on shots beyond 200 yards and having the magnifier swing to the side is very convenient for closer shots. The Vortex VMX3 Magnifier is great value for it's price plus it has an unconditional lifetime guarantee.
Pros: Very good optics
Cons: Thick rubber covering
This review was written in the old system and had content requirements that are different than reviews written today.