We made seveal upgrades from the frame.
First of all, nylon standoffs is upgraded to aluminum alloy standoffs,
which strengthens the frame and stables structure.
Second, We added the receiver fixing bracket.
Third, we upgraded the arms. The arms are upgraded from 4 individual arms
(2.5mm thicness) to 2 integrated arms(3.0mm thickness). It is more easy to
disassemble, sturdy and durable.
Last, the V2 version only needs 4 screws to fix, and the arm can be replaced