Thanks, Russ,russ_watters said:That's for cutting down the brightness when you view the moon.
The Celestron 130 SLT tube cap is designed to protect the telescope's optical tube from dust, moisture, and other environmental elements when not in use.
No, the tube cap should only be used when the telescope is not in use. It is not designed to be used while the telescope is in operation.
Yes, the tube cap is specifically designed to fit the optical tube of the Celestron 130 SLT telescope. It may not fit other telescope models.
While the tube cap is not necessary for the overall functioning of the telescope, it can help prolong the life of the optics by keeping them clean and protected when not in use.
Yes, the tube cap can be purchased separately from the telescope. It is also included in the original packaging of the Celestron 130 SLT telescope.