This item has been Discontinued and limited to existing inventory, may have minor blemishes.
Interlock for an Andersen Prefinished Terratone gliding door built from 1966-82. This will fit the three panel door. It is Terratone in color. It goes on the operating panel on the side with the lock. It has a cutout in the center to go around the lock mechanism. 

79-7/16 inches long.