Variants of a mold are catalogued separately, so each one has its own sets and minifigs. Check these too if something you expect is missing here.

• 3855a Glass for Window 1 x 4 x 3 [Old Style - Circular Indent] Mold of this part
• 3853 Window 1 x 4 x 3 this part is a pair of it
• 4033 Window 1 x 4 x 3 Train with All Studs Hollow Pair of this part
• 6556 Window 1 x 4 x 3 Train with Shutter Holes and Solid Studs on Ends Pair of this part