Take off your power source! It seems that while the tag changes from Infusible to Infused while powered up, it also acquires the No Trade tag. Once it goes back to Infusible, the No Trade tag goes away.
Moot point, since the next patch will be changing all of these pieces to Attuneable...
There is no listed Attuneable flag on it however.... you can NOT trade it after you put it on. -Will go on with out the pop up requester of are you sure you wish to attune it -Will ninja add NoTrade flag after you put it on
Got this off of a trash mob in the room where Isabeaux Darkdreamer spawns but it's magic, lore, infusible...not attuneable flagged so can be traded after being worn.