This adapter allows to use EF and EF-S mount lenses on Micro 4/3 camera system.
It has "positive lock" mechanism so there isn't any play between the adapter and lens mount.
It is designed to work with cine lenses ( manual focus and aperture ring).
Andrew Reid's review on eoshd.com :
http://www.eoshd.com/2015/03/locking-canon-and-nikon-adapters-for-e-mount-sony-a7s/
-- SHIMMABLE FLANGE ( COMPATIBLE WITH ZIESS CP.2 SHIMS) --
-- AF AND ELECTRONIC APERTURE DO NOT WORK --
-- INFINITY FOCUSING --
-- SUPPORT BRACKET WITH 1/4"-20 AND 3/8"-16 MOUNTING POINTS --
-- 0.002mm ACCURACY --
-- EF PORT CAP INC. --
-- MADE OF MILITARY GRADE ALLOY ( AW-7075 ) and STAINLESS STEEL --
-- BLACK ANODIZED --
-- MADE IN UE ( POLAND ) --
-- DIRECT FROM THE MANUFACTURER --