Used on a German Luftwaffe Messerschmitt ME-109. I base this on a couple of war photo's, although I have seen this and other fighters with different types of insulators, this may not be exclusive to the ME 109. About 8 inches in length and very light. Constructed of Lucite or possibly a similar plastic and aluminum with metal stirrups. Lucite was discovered and trademarked in 1931 by Dupont and was in very heavy demand during the war for use in bomber and fighter aircraft windshields, nose cones, and gunner turrets. This one may be Lucite but I am sure that at some point prior to the war there were no dealings with Germany. Around 35,000 ME-109's were built and are described as one of the most feared fighter aircraft of the Luftwaffe.