■ This is an adapter ring that can be magnetically attached to your lens filter. ■The "B" is attached to the lens side of your filter. A or "C" adapter is attached to the lens by magnetically attaching the adapter to each other. ■ Can be used when the filter diameter is 67mm. ■ Screw the filter on the lens side of the filter in the same manner as a general filter. - The adapter ring itself has magnetic force. ■ The B lens side has no cut grooves, so this product cannot be used alone.