Just purchased a new mac book pro that has thunderbolt 3 connections but all my WD 2TB drives are firewire 800s. Only thing I have found that can connect them are two apple products which keep disconnecting and reconnecting. Its a Thunderbolt 3 to thunderbolt 2 cable and a Thunderbolt to Firewire adaptor cable. They worked for about a week and now today have stopped. Apple support were useless as were the local store.