weird symbol on the left of the special effect on weapon

[ganjafiut]

it looks like 2 rectangles with arrow in between them, anyone can tell me what that means?

[Gameo]

Transferable affix, max the familiarity on it and soul match it to another item to transfer it, so long as it doesn't conflict with another affix that may already be in the same pool

[ganjafiut]

thanks