From Leica Wiki (English)
- Code name - VALOO - 16620
- Production era - 1949-1961
- Type - Combination lens hood and diaphragm adjusting ring for Elmar (III) f= 5 cm 1:3.5 with 36 mm front diameter. Filters can be mounted in the front of the hood
- Reference - Page 106 of Dennis Laney's Leica 1984 Accessory Guide courtesy of Mike Butkus.