This is the Case Back Crystal fitted to the 3573.50 FIRST AND ONLY WATCH WORN ON THE MOON steel case back 145.0811.
These are Omega supplied service case back crystals for the 3573.50.00.
This was fitted to the model stated above but you can exchange it for the crystal in the limited editions APOLLO 11, GEMINI IV, SNOOPY sapphire case back if you want to modify your watch to have a clear crystal to view the movement.
062sn5126 Omega Speedmaster Case Back Crystal for 3573.50 145.0811
Items can only be returned if either faulty, in the case of the item not being required then it must be returned exactly as received. For example if the item is new in a sealed packet and/or has protective covers in place then it must be returned the same otherwise item is no longer new and the value is greatly reduced, these items can only be returned/refunded by agreeing a lower value with Swiss Limited Editions before returning reflecting the new lower value of the item.