Fan Size: 8 inches / 20 cmHole Cut-Out Size: 260 mm x 260 mm (10.2" x 10.2")Air Volume Capacity: 265 CFM / 450 CMHFan Rotation Speed: 1207 RPMPower Consumption: 25.7 WattsOperating Noise Level: 41 dB (low noise Q-Blade design)Motor Engineering: Ball-bearing condenser motor equipped with a built-in safety thermal fuse.(THIS PRICE 2 UNIT )