This Eg series Precision Matte Grid Lines Eg-D Interchangeable Focusing Screen from Canon provides three horizontal and five vertical etched grid lines to facilitate easier composition and horizon alignment. This "D" type focusing screen assists in keeping straight lines in a subject straight, positioning subjects off-center, or by keeping compositions in a series consistent from one shot to the next. The camera's AF points remain fully visible when using this screen. Compatible with Canon EOS 5D Mk II and 6D