The unique LEE100 Tandem Adapter enables two LEE100 holders to be joined together, offering photographers room for greater flexibility, creativity and control. Installing the adapter is a simple matter of slipping it into the front slot of the first holder; the second holder then clips onto the adapter in the same manner the first one does to a LEE100 adapter ring. Two small lugs on both sides of the adaptor act as guides for correct positioning of the adapter in the holder. The joined holders rotate and lock into place independently, allowing the photographer to position the holders at different angles when needed. This is beneficial when a ND grad filter needs to be vertically positioned to cut glare coming from one side while the other remains horizontally placed to reduce bright light from the rest of the sky. Or, the ND grad filters can be creatively positioned at differently angles to create certain moods or effects.