21 inch arm

Thank you for your patience during this incredibly busy season. I apologize for the long wait.

Your balance is a bit of an odd design. It looks like it might be a heavy duty, commercial grade part, but the window itself looks like a typical residential setup.

Before we go any further, can you kindly tell me the diameter of the gray tube? Can you also tell me if it has a code or name stamped on it anywhere? If so, we have to see a photo of it.

I may have more follow-up questions for you, but let's start here since what I ask later will be impacted by how you answer now.