The BookBook Cover for iPad + Keyboard is designed to fit an iPad plus a thin, attached, external keyboard such as the Apple Smart Keyboard Folio or Smart Keyboard, but it will fit other combinations of tablets and keyboards that measure up to:
11-inch size: 9.76" x 7.28" x 0.63" (248 mm x 185 mm x 16 mm)
12.9-inch size: 11.06" x 8.74" x 0.63" (281 mm X 222 mm x 16 mm)