ARRI Signature Prime and Signature Zoom lenses are equipped with the LPL (Large Positive Locking) lens mount. A wider diameter and shorter flange focal depth allow LPL lenses to be small and lightweight, with a fast T-stop and pleasing bokeh—a combination of features that would not be possible with the old PL lens mount.
ARRI has shared LPL specifications openly and free-of-charge across the industry, establishing the LPL lens mount as a standard interface between cameras and lenses. ARRI LPL lens mounts are available for ALEXA 65, ALEXA 35, ALEXA LF, ALEXA Mini LF, ALEXA Classic/XT/SXT, ALEXA Mini and AMIRA cameras. In addition, third parties offer LPL lens mounts for cameras, director's viewfinders, and lens testing tools, so ARRI Signatures and other LPL lenses can be universally used.