The Retro watch is a very distinctive watch. The watch has angled lugs which make the watch stand out on the wrist, which also aids comfort. The real distinction is the way the strap follows precisely the contour or circumference of the watch; to aid this the end of the strap where it fits the watch is curved. Most straps have squared off ends at the watch end, which results in a gap between the watch and the strap. So this distinctive feature is the decider in which strap to purchase. The red strap is now discontinued, and Mondaine will also phase out the black versions in due course.
Just to remind you, this is the watch.
The standard length versions of the straps have now been discontinued and are no longer available. The only substitute is now the XL version, which isn’t as long as it sounds. For reference, the dimensions are below, you may wish to compare the measurements with your existing strap:
Buckle end (excluding the buckle) is: 14mm width is 65mm, the 20mm width is 85mm.
The tail end is: 14mm width is 125mm, the 20mm width is 130mm.