The Greenlight design of this cable improves upon the shielding design of the original D710 cable. The D710 does not use twisted pair CAT5 (Ethernet) cables!
The designers instead use non-twisted wires, one of them being used to provide the cable shielding. As some users have already encountered, using a standard CAT5 cable for the microphone extension may result in noisy transmit audio.
Green Light Labs sells a nice SHIELDED cable (Cat 5 is Unshielded Twisted Pair - UTP)
for the Kenwood TM-D710Ahttp://www.greenlightlabs.com/store/index.php?manufacturers_id=10