For the weight weenie in you (whether you've just lost a ton of weight or you actually think a carbon belt buckle will shave some grams off your commuter kit)..... These are super functional and I think they look awesome.
After a long season of riding hard, I lost some weight. I needed a new belt and I knew I wanted to make it myself. I'd seen belts made from climbing webbing before and the only difference any of them had would be in the buckle. I didn't know what I wanted to use for mine until I saw two headset spacers laying on my coffee table. They'd been leftover from a recent bike build and they were an obvious choice to use as belt rings. I ended up gluing two 3mm spacers together for each ring so next time I'll just buy thicker spacers to skip this step.