Genuine Intermediate L39 Ring 7mm (Light Alloy Chrome Finish) Product Details: This is the "B ring," also known as the 7mm ring, with the "B" marking, which was listed in pre-war catalogs for Leitz L extension rings, often used in combination with ZWTOO. Made of light alloy with a chrome finish, weighing approximately 12.1g. Condition: The exterior is very clean, but there is some natural peeling of the anti-reflective black paint on the inner edges due to aging. While not in like-new condition, the knurling and the "B" markings are almost perfect, making it an excellent condition item.