Apologies. 23 x 17 x 8cm are the dimensions of the one with the biggest surface area. I have a narrower, taller one too. The bag from Amazon arrived today and it was crap. It had Velcro straps which wasn't the end of the world. However, I couldn't even get them unfastened because the Velcro went through the loop. That is on its way back this evening. I think I might have to concede and get another pannier rack on my road bike. Under duress.