These clocks come in two shapes (round and square) and two sizes. Each clock has a keyhole at the back for easy hanging on a wall. They're made from an acrylic material that looks like glass but is more durable and sturdy..: Material: 100% acrylic.: Round and square shape options.: Two size options (10.75''×10.75'' and 8''×8'').: Requires one AA battery (NOT included).: Includes keyhole hanging slot