Replacement part can be ordered from: Zhengte U.S.A., LLC, Chino, CA 91710. 800-867-9018 Mon - Fri., 8:30 am to 4:30 pm (PST). They have a website too but, it just tells you to call them (or full out the form and they'll call you).

That said, I recommend you buy another complete unit, use the structural components to strengthen your existing one (put the new poles half way between the existing by cutting the existing in half, putting in the new poles by drilling and riveting the connectors and poles). That's what I did and then just covered with the new canvas. It makes for a much nicer and stronger unit. Might even cover with some corrugated material so I can stop replacing the canvas.

I have purchased parts by calling the provided company in the past. Initially it was obvious the guy I dealt with couldn't have cared less about getting me the parts I needed. After a little internet searching I tracked down the contact information for the President of the company in China and sent him an email. Service became exceptional after that.

One last thing, seems I cut some length off of the poles I cut in half to account for the extra length of the coupling. That way the canvas still fit. Not sure, it's been awhile. Just keep that in mind if you decide to do that.