Sony has registered 2 new wireless headphones with the FCC, the WI-C200 and WI-C310. The FCC documents do not reveal much except that both models will finally feature Bluetooth v5.0. Judging by the model numbers, WI-C200 and WI-C310, I would imagine the upgrade is not significant in nature and is mainly only for adding a new Bluetooth version and the only difference between the 200 and 310 might be either colour options or only the 310 offering hands-free calling, but I feel removing such a feature from the WI-C200 would be a poor decision.