I have an AR with a M16 slab side upper.  Red dot optics are new to me and what works with standard AR mounts.

I have read about the S.P.O.T. Mark III torture test.  According to my wallet, it seems like a very good alternative to an Aimpoint for plinking.

I cannot find the following information in searching the threads.

Will the S.P.O.T. Mark III with A.R.M.S. #39 A2 Plus Mount co-witness with the iron sights as the optic comes from the factory its mount?

I appreciate anyone knowing if this will work.

Edited to add the referred links.

Don't know about the ARMS #39 but I have a SPOT with the mount that it came with and it co-witnesses perfectly with Troy Flip BUIS.

MadDog

probably in the lower third/fourth of the optic.

I don't understand:  lower part of optic?