Looking for the perfect window product to complement your home? Thermo-Twin’s bay windows are each custom made to fit your needs. Customization of these product starts from the ground up, with custom sizing options available to fit the openings in your home. Additionally, our bay windows incorporate a custom-built wood buck or window frame, available in two variations: Oak or Birch. The buck assembly for your windows to be installed into includes both a head and seat for proper anchoring.