I used Challenge Vulcano tan wall tubs on one of my bikes. They’re another great-looking tyre and overall I was very happy with them. My only criticism was longevity issues, as the tread rubber hardened and cracked quite quickly. The outer casing was basically dead before I’d worn the tyre out. I would buy them again, but I can’t help but compare them to the 4 year old Conti Giros that stood in the sun for 6 months during lockdown on a bike that was stuck at work and were completely fine…I considered Challenge for some recent builds but they get some poor reviews for durability so I didn't bother.