The jetons are almost 43mm in diameter and slightly thicker than normal chips. They are quite light, weighing only 5 grams. The 10.000 plaques are a bit smaller than a bridge size playing card and weigh 28 grams. The 25.000 plaques are a bit larger than a bridge size playing card and weigh 38 grams.
I loved playing with jetons from the getgo, but they do feel almost alien in nature compared to other (high end) game tokens. They weren't really meant to be used in tall stacks and are certainly more slippy than clay chips, but I get more excited about having these in play than with any other set I own.