This is the Looking Glass. It is an Argon Gas filled Container with circulating helium in liquid form to keep it cool.

https://www.thelivingmoon.com/42stargate/03files/Project_Looking_Glass_LANL.html?utm_medium=ios_app&utm_name=iossmf&utm_source=share

This is exactly what we are using now. Looking Glass ceased to work as timelines converged on 12/21/2000 the end of the Mayan Katun.

i thought it couldnt see oast 2012?

Looking Glass couldn’t as all timelines converged. But, the Yellow Cube and Stargate are not bound by time. Looking Glass had issues as we approached 12/21/2000 and the closer to that date any changes to their present timeline ceased to alter the future. Thats why it was disassembled and put in storage since it no longer worked.