Thermostat Guard, Transparent Cover With Mounting Plate and Mounting Ring, fits 1C20, 1C21, 1C26, 1C30, 1D30, 1D36, 1D56, 1E30, 1E31, 1E35, 1E56, 1F30, 1F35, 1F36, 1F51, 1F56, 1F57, 1F58 Case Size =12