Orion 80mm ED Lens Cap Question

My 80mm ED came with a cap that fits over the lens shield. The cap itself has a 2.5" stop-down opening with its own separate cap.

What is the intended function of stopping down the aperture like this? Lunar or solar observation?

Clear Skies
Ed Kessler

Ed,
#1-DO NOT USE IT FOR SOLAR OBSERVING!!! Only use the prper solar filter.
#2-Possible for lunar use buit a polarizing filter would be best for lunar