Ikea BILLY Bookcase Shelving Unit Height Extension - Birch Veneer - used, in good condition, has some chips & scratches (see photos for condition). Assembled - $20 firm (height extension only, no bookcase shelving unit included) PRODUCT SIZE: Width: 31 1/2 " (80 cm) Depth: 11 " (28 cm) Height: 13 5/8 " (34.5 cm)