Summary A protective roll cage for the Xtreem Quadcopter. It's fun to drive around on the floor and chase the cat! I use 1/16 dia alum tube for the bar that's shown. But carbon fiber would be better if you can find it The alum. is avail at Ace hardware or Osh. I hand drill the holes after printing with 1/16" dia. bit. Update TAP Plastic has .07"dia carbon rod. And they have 1/16" dia acrylic - which works great - it has good spring to it.