This pipe is exactly 2 1/4" OD - as you can see the screws provided do not reach the other side. I had to buy longer bolts and nuts. I assume the packaging is correctly labeled for this size of pipe. Also, the metric thread didn't quite match the closest metric thread I could find in HD. Nicely made block - it's polished, has silicone inlays so whatever you wrap doesn't scratch it, but that's the only reason I gave it 2 stars.