With this ring you can use the Kowa adapter shell with the Zeiss adapter rings made for Zeiss Harpia and Gavia. The Otterbox ring is threaded into the Kowa shell for iPhone, Samsung, Vario, etc., then the Zeiss adapter ring can be threaded into the shell.
These rings from Zeiss fit with Otterbox to:
Gavia
Harpia
These smartphone adapters fit together with rings:
iPhone
Samsung
Vario univeral adapter