http://www.zeiss.com.hk/camera-lenses/en_hk/service/download_center/touit_e-mount.html

Touit 2.8/50M E-mount:
A firmware update to Version 02 is now available for the Touit 2.8/50M with E-mount. It corrects the following behaviour that may have occurred with the previous lens firmware version with particular camera menu setting and in particular situations:
clearly noticeable shutter release delays when pressing the release button with activated flash
‘hunting’ for the focus point with the camera in AF-C mode
all Touit 2.8/50 macro lenses for E-mount cameras ever delivered already support phase detection autofocus and the fast hybrid autofocus of newer Sony E-mount cameras with their proprietary firmware.
Touit 2.8/12 E-mount & Touit 1.8/32 E-mount:
An update to firmware version 02 is available for the Touit 2.8/12 and Touit 1.8/32 lenses with E-mount. With this version, the lenses also support phase detection autofocus and the fast hybrid autofocus of newer Sony E-mount cameras.