With this adapter, the camera can be rotated around the optical axis, so that the sensor can be rotated to frame the image in the best possible way. Expensive focuser systems for eyepieces are often already rotatable. With this adapter, you can upgrade this option.
The image shows the adapter in combination with the Skywatcher Flattener 0.85x EvoStar 72 ED.
The rotator works with Evostar telescopes built from December 2019 onwards. Older models cannot be focused in combination with the Skywatcher 0.85x reducer!