MADE IN USA. The extended length focusing ring is precision-machined from aircraft grade aluminum and is designed to fit standard 9mm diameter lens assemblies. It is nearly 1/2' long with a knurled outer surface and allows easier focusing without burning your fingers. The outside diameter is sized to fit commonly-used protective lens caps. A taper is machined into the output end of the ring which gives it a 'rocket nozzle' appearance. Red anodizing matches our red anodized aluminum heat sink.
Protected by U.S. Patent no. US 686,097 S.