The EC neck chord is perfect for the EC camera and having the same clip as on the chains for the C, BL and LX cameras can be also be marked up with beads (sown on thread) at the appropriate length to act as a rough measuring chain.
Using a chain, particularly with a small camera like the Minox A, AX and EC instils confidence that you will not drop it, or if knocked out of your hand will not fall far. If you hold a Minox Riga (which has no chain fitment) this becomes even more apparent. The stainless steel is more slippery, the camera surprisingly heavy and frequently they are hard to open- add that to the cost of one of these collector cameras it puts you on edge using one. The chain also is long enough to wrap around a belt several times so it the camera falls out of side pockets it will not travel far. Unfortunately there is no wrist chain, similar to that of the Minolta MG-s with which it can be secured in a belt case and to the belt.