PocketWizard CM-E3-P MD PreTrigger Cord Hasselblad H1 Features:
For remotely triggering the electronic shutter release of cameras with a Canon E3 or sub-miniphone (2.5 mm or 3/32 inch, stereo or mono) remote terminal.
This cable contains a Pre-trigger switch. When enabled, the camera behaves as if the camera's shutter release button were held half-pressed continuously. This makes the camera respond more quickly and consistently, but also consumes the camera's batteries much more quickly. When disabled, this cable functions identically to the CM-E3.