March Eyepiece Spotting Scope Adapter
The Eyepiece extension ring included in the kit extends the eyepiece so you can use it with your eye attached to the eyepiece. As it is covered with rubber, you can look into it like a binocular or a spotting scope. The difference with a spotting scope is that you can use the same rifle scope (same model, same reticle) as the shooter.
If a March Scope is attached somehow to a solid tripod for view, this eyepiece ring attached the eyepiece of the scope can be used. Like replacing a regular spotting scope and using a rifle scope which has a reticle.