Image Item No. Description By  bslot03bL  Brick 2 x 3 without Bottom Tubes, Slotted (with 2 slots, corner left) Catalog: Parts: Classic 1  bslot03bR  Brick 2 x 3 without Bottom Tubes, Slotted (with 2 slots, corner right) Catalog: Parts: Classic 1  bslot10  Brick 2 x 10 without Bottom Tubes, Slotted (with 1 slot) Catalog: Parts: Classic 1  bslot17  Brick 4 x 4 Corner without Bottom Tubes, Slotted (with 2 slots) Catalog: Parts: Classic 1