This will not have a co witness factor as it is a magnified item and those are not co witness
Uh, sorry Brandon, wrongo, this is not a magnified optic; this 4s model comes with a QD absolute co-witness mount and a second low mount for shotguns, et al. You can buy a .22" spacer from sig to make it lower 1/3, just beware ,you need to buy four, longer screws separately from them to attach it. The spacer comes with the 4T version of this sight but that ones more expensive - not worth it.