Unfortunately, I wasn't up to speed on the nominal sizings that are used for these products. My canopy was advertised as a 12 x 12, but the frame is 13 x 13, measured at the ground when the legs are out. The top frame is just under 10' square and they sent a top that was just over 8 x 8, which their customer service tells me is the correct size for their 12 x 12 slant leg model. Luckily, I was able to use the new top on an older 10 x 10 canopy I had around. Do yourself a favor and make sure the measurements match up before you order!