Keep your hands dry and easy! Moss Cleaning!! Floating type magnetic wiper; Strong magnet supports glass thickness up to 0.3 inches (8 mm); Floating type, so it wont sink into the bottom of the aquarium even when separated; Even the uneven shape of the wiping surface scrapes away stubborn moss. Width 1.3 x Depth 2.8 x Height 3.2 inches (3.3 x 7.2 x 8.1 cm) when combined with 2 cm)