HOYA Sq100 Geared Adapter is a metal ring with a gear component that serves to attach Sq100 holder to the lens and to rotate Sq100 polarizer inside the holder frame with the polarizer control wheel.
When attaching the Sq100 holder to a lens with an 86mm filter size, use the 86mm-86mm geared adapter. When using the system with an 82mm filter size lens, use the 86mm-82mm geared adapter. For other lens sizes, use the adapter rings which are available in all common sizes.
In order to avoid purchasing one of those counterfeit filters we highly recommend to purchase only from official retailers that are recognized by HOYA's official global distributors. Prior the purchase kindly inquire and verify whether a retailer is authorized by HOYA global distributors. You may find the contact in the HOYA global distributors list.