On paper, the PRX falls into a sweet spot. Tissot states a 40mm case diameter, but our calipers show it’s a bit smaller than that, though that’s not the only discrepancy we found. Tissot lists the thickness at 10.9mm and we’re showing 11.2mm – still pretty thin but with this case and bracelet, these numbers matter. This brings us to the most important numbers of this case, and that’s the “lug” to “lug”. Tissot lists the total length as 39.5mm, which is measured from the break point of the top plane of the case. Measured from tip to tip, that number is 44mm, and measured from the actual bracelet break point (where you’ll find the lug holes), we’re looking at nearly 51mm.