Objective lenses in conventional CD players have a longer working distance, or focal length, than lenses designed for SACD players.[lower-alpha 4] This means that when a hybrid SACD is placed into a conventional CD player, the infrared laser beam passes the SACD layer and is reflected by the CD layer at the standard 1.2 mm distance, and the SACD layer is out of focus. When the same disc is placed into an SACD player, the red laser is reflected by the SACD layer (at 0.6 mm distance) before it can reach the CD layer.