Partly evacuated, with two bulbs each holding a set of vanes. At its centre is a fine pivot supporting four lightweight metal arms; one side of each vane is darkened and the reverse side is bright. Mounted on a round base.

We are manufacturers and suppliers of the Crookes Radiometer (double), serving Algeria, Argentina, Australia, Bahrain, Bangladesh, Belgium, Bhutan, Brazil, Cambodia, Cuba, Cyprus, Denmark, Ecuador, Egypt, Ethiopia, Finland, France, Georgia, Germany, Ghana, Hungary, Iceland, Italy, Japan, Jordan, Kenya, Kuwait, Malaysia, the Philippines, Tanzania and Uganda.