Abstract: A frictional coupling, especially synchronization device of gear mechanisms, with at least two coupling bodies (1, 2) which come into frictional contact upon engagement of the coupling, wherein one coupling body consists of one ring-shaped base body (3) of metal with at least one flat, conical or cylindrical carrier surface, to which a frictional layer made of organic or inorganic frictional material (4) is attached, and at least one other coupling body of a counter body (8), preferably also made of metal, and has a counter surface which works together with the frictional layer, is further developed for closed systems such that clamping or damage to the edges can be avoided with continued unimpaired function and the usage in the new condition is facilitated.