Lock Ring for Kowa 16-H to use it with Rectilux HCDNA

Description

Lock Ring for Kowa 16-H to use it with Rectilux HCDNA
Front side - M75x0.75 male thread and M72x0.75 female thread
Rear side - M68x0.75 female thread
This adapter replaces front ring of Kowa 16-H and serves few purposes:
It locks focusing mechanism of Kowa at desired position (infinity for most applications)
It allows installation of Rectilux HCDNA attachment
It allows using standard 72mm screw-in filters (if no HCDNA installed)
Made of high quality aluminium alloy.
Important note:
This was not my idea, so I've just made couple of them while original manufacturer was on vacation, and people wanted to get such item sooner. Please search for HTN lock ring for original items. Or ask me to make more if original manufacturer is unavailable or out of stock for a long time.