Image Item No. Description By  bslot01  Brick 1 x 2 without Bottom Tube, Slotted (with 1 slot) Catalog: Parts: Classic 1  bslot04a  Brick 2 x 4 without Bottom Tubes, Slotted (with 2 slots, opposite) Catalog: Parts: Classic 4  cwindow01  Window 1 x 6 x 4 Panorama, with Glass for Slotted Bricks Catalog: Parts: Classic 1