Hi, I've a Phonak PFE, IE7 and SF5 Pro, all with original cables long gone... :-/ My Sennheiser IE7's "kevlar" cable began cracking after 4 months. Earlier two cables slipped out of the T-piece. On the SF5 i put cat5 ethernet twisted pair, durable, but too heavy duty and not flexible. I think the main problem with the stock cables is temperature, rain and skin oil. Outdoors below 10degC (50F) hardens the cable and then movement stresses the material and it cracks faster. Water and oil harden the cable as well. And then it is bye-bye quickly... I'd like to get a little more mileage out of original/replaced/repaired/... cables than just 4..6 months. Appears silicone cable would be best. As used in multimeter probes, for example, inexpensive and durable (but those I can find are 1-strand and very thick). Or this Cicoil cable brand used in one hearing aid. Hard to find any as small <10meter batch though. Any suggestions for good cable? From what place did you order?