This small pane of glass in a frame made of black metal looks like a small hand mirror at first glance, but when a creature spends at least 1 minute staring into its reflection, the image shifts and changes, showing the landscape of another plane. If the lambent window is activated on the Material Plane, it shows the corresponding location on the Shadow Plane, along with any creatures at that location. Likewise, when used on the Shadow Plane, it shows the corresponding location on the Material Plane. This item only allows those staring into it to see the corresponding location on the other plane; they cannot hear through or gain other sensual information about the other side by way of the window. This effect can be used for up to 10 minutes per day. Those minutes need not be consecutive, and the 1 minute it takes to activate the lambent window does not count against this limit.
A person holding an active lambent window can use it as a special focus when casting plane shift or using plane shift as a spell-like ability to reach the specific location shown in the mirror, rather than 5–500 miles from the bearer’s intended destination.