QandXFrom superaudiofriends:
The Drop HA-FDX1 has a satin finish and doesn't have the ridges on the endcap. The HA-FD01 is shinier.
The Drop FDX1 is essential the same as the FD01 with minor changes and community tuned filters.
Same dual carbon 11mm driver (DLC diamond like carbon inner dome and black carbon outer ring)
Same great pleather JVC magnetic case
Same great robust OFC cable; On the slightly thicker, heavier side, yet very soft and pliable; virtually memory free with excellent tangle resistance
Same CNC machined Stainless Steel housing minus the knurled ridges; housing is a two piece design that swivels to accommodate wearing up or down and any shaped canal
FDX1 ditches the Titanium and Brass nozzles and comes with 3 Stainless nozzles
1 nozzle is empty for stock FD01 tuning and/or modding, and 2 nozzles contain community tuned filters