Carefully pull up on the Fermier len to release the latch.

Use a screwdriver to release the latch on the knob and push it out from the inside.

Remove the keystone knob.

Component Description (Fermier len): Installed between the LCD screen and the mirror to achieve keystone correction function. Made of PC material. An ABS injection-molded bracket serves as a buckle and is fixed to the knob. Dimensions are 155mm long, 83mm wide and 9mm thick (including ABS bracket). The lens itself is 1.7mm thick. Weight is 23g.

Component Description (knob): The knob has a diameter of 35mm and a height of 25mm. It is made of ABS plastic injection molding. Weight: 5g.