The 13377-S is a special remote shutter release cable called a pre-trigger cable. A pre-trigger cable controls both the half-press and full-press function of your remote camera’s shutter release. When a camera is “pre-triggered”, it is like holding your camera’s shutter release button in the half-pressed or metering/focusing position.
From 1/8″ (3.5 mm) stereo mini-phone to Sony’s multi/micro USB port. Cable Length: 3′ (91 cm) straight. Compatible with PocketWizard MultiMAX, MultiMAX II, and Plus III models only. For Sony’s Alpha cameras and others with Sony’s multi/micro USB port.
Note: Can be used with PTMM Adapter allowing you to keep the camera awake.