If you look closely at the photos and draw a line straight across at the extreme of the diameter between the lugs it will give you an idea, it seems to be about 50mm, certainly not too large. This is probably the best looking Heritor to date on Drop; I'm not a fan of open heart but the balance with the night/day and 24-hour dial give me undertones of a regulator watch at a glance and the nice texture on the dial with raised indices leave a more expensive look, probably would've preferred Roman numerals: but that may have polarised some who wanted a little more contemporary with the sporty baton look. Nice leather band with that european curve at the lug end. All in all for $99 a nice buy! Even if it is Chinese movement there seems to be a bit of value in the aesthetics , if a miyota or seiko auto probably hope for at least another $60 or so on retail. If a budget buyer under $200 then this is a really decent buy. My preference the yellow gold and brown strap, probably because of the traditional look.