After few weeks of using black silicone cover became grey silicone cover.
Too much dust on it and not very pleasure to touch it. Same problem with black control ring.
Repeating again and again after regular two-day cleaning.
May be you had to build it with TPU material for first and plastic for second.
I can't find chinese covers from Ali for previous FiiO models, so looks like that a problem above will be always with me :[
Edited by Nuke142 - Today at 1:42 am