4MM ARM BRACE FLOSS 3.0 LITE (choose size)

works perfectly :)

good for when your arms start getting a little spongy and you want to keep using them a little longer. Dont forget to use 2 longer screws where this cross bar bolts onto the arms and motors

5 inch version

Fits fairly well. I had to unscrew the arm screws to loosen it up and then pull the arms apart to get the holes to line up, but it wasn't too hard. Once everything was tightened back up, it was extremely rigid. Note that you need 4mm longer screws for two of the motor screws because of the additional thickness of the brace. Adding a front and back brace to my quad added about 11g of weight, including the longer screws.