Genuine leather replacement watch straps intended for Mondaine Swiss Railway watches. Mondaine logo on the reverse of the strap and on the buckle.
The width of the strap is measured between the lugs on the watch which holds the strap in place. On the reverse of the strap, on the “tail” end (as opposed to the buckle end) is, should be, a number – 12 = 12mm. If this has been worn it might help if you shine and angled light onto the area, as it is embossed, the number can often be found. You can measure between the lugs holding the strap to the watch, but be careful as there are only 2mm separating the sizes. Don’t measure the strap as this often distorts in use.
If you are unsure of which strap you need, this page may help you.
Fitting the replacement Mondaine swiss railway watch strap is easy, if a little fiddly. The video on this page will give an explanation.