With this black strap you had a choice of one – 22mm with an extra long option (Mondaine now inform us that the 16mm version is no longer in production). This refers to the width of the gap between the two stanchions which house the strap. If you are unsure, the size is stamped on the inside of the watch strap.
The total length of the XL strap is 92mm from the securing point to the buckle pin position, plus 103mm from the securing point to the last hole; total 195mm. Please note that the XL version has a reinforcing strip down the length of the strap and it has a tapered tail: See image:
Fitting the Mondaine watch strap is easy, but is a little fiddly – a video explaining how to swap your strap is at this page.