Spacers are used to co-witness a red dot sight with iron sights of the firearm. You can have the sights aligned with the red dot (full co-witness) or at the bottom part of the optic’s field of view, with the dot above the sights (lower 1/3 co-witness).
Read our Blog post about Absolute and Lower 1/3 Cowitness here
Our customers are often confused by the terms adapter, riser, and spacer. These are used for the same purpose but have different characteristics. The manufacturers of mounts are not consistent when it comes to naming these types of mounts.
For example, some mount manufacturers use the term ‘riser’ to refer to a mounting part that is referred to as ‘spacer’ by other mount manufacturers. Furthermore, some companies use the terms ‘riser’ and ‘spacer’ to describe a mounting item that is referred to as an adapter by other companies.
To eliminate confusion, we have relied on our own explanation when categorizing adapters, risers, and spacers.
The mounting standard on the bottom and the top is the same. For example, it attaches to a mounting surface designed for the Trijicon RMR mounting standard and has a Trijicon RMR mounting surface on top.
It does not feature any parts, such as a lever or a screw, that would allow it to be fixed on the mounting surface below. It is fixed in place with the help of other mounting parts, usually with screws that go through the spacer.
Red dot sight spacers are almost exclusively made from aluminium.
They are produced by:
Aimpoint, and many others.