Radiometer with four lightweight metal arms.
- Includes black and white vanes in color
- Mounted on round plastic molded base
- Glass bulb with 70 mm dia.
Comprising partly evacuated glass bulb approx. 70 mm diameter, containing at its center a fine pivot which supports four light weight metal arms. One side of each vane is blackened, the reverse side is bright. Mounted on round plastic molded base.