The M&P Handcuffs have been my favorite standard sized handcuffs, however when looking for variants that would work better with my cuff wraps, this Model 1-1 version has been working out as a great option.

Hence universal being in the name, the idea of this Model 1-1 design is that it can can accommodate more wrist sizes including both bigger and smaller than average. Looking online it appears the main claim is "12% larger for big wrists and close 11% smaller for thin wrists", which likely seem to be fairly small numbers to most, however that little bit actually seems to help out a lot. 

One of the downsides to the cuff wraps is that the padding fills up the normal cuff space pretty quick making them only appropriate for small wrists, otherwise oversized cuffs are needed which can be a bit bulky and need bigger rings to route through. There are all kinds of cuff manufacturers, but on some such as S&W, the oversized handcuffs are just the Leg Iron versions with a short chain connection. As one can see looking at the comparison pics, the Universal cuffs are basically a blend of the traditional size and oversized size, leaning a little more on the traditional size direction.

Most cuffs can open up fairly big in one axis, yet the main constraint is the other axis; the distance from the inner bottom to the hinge. This is about 2" on a standard size handcuff while the Model 1-1 has about 2-3/8" of space there. That little bit of extra space goes a long way to fitting more wrist sizes, using cuff wraps or not.

For considerations, the Model 1-1 swing arm starts to stick out from the main body during tightening sooner than on classic sizes. It isn't a deal breaker, however it can be a bit of a snag hazard. Fortunately if using the cuffs on the medium and larger sizes the stick out factor won't be a problem. As expected the size change will limit what pouches the Model 1-1 cuffs will go in. I was semi surprised they fit in the circle snap style pouch just fine, for the open slot style however it doesn't quite fit all the way. When tightened all the way and at an angle, one can get something around a 80% fit. The main thing I'm sad about is the Model 1-1 cuffs have a traditional push pin double lock and a M&P style lever lock is not available. I suppose others won't care as much if they haven't been spoiled by the M&P level locks, but not needing a key to double lock is certainly missed on my end.

Maybe someday S&W will make a lever lock version of these universal cuffs, but until then the Model 1-1 still offers a great handcuff option that can fit those who were borderline fits with standard sizes. Since not quite full on oversized, the Model 1-1 can be carried and deployed on most of places standard sized handcuffs are. Thus, for the vast majority of situations one could carry less just bringing 1-1 cuffs instead of also having to bring small wrist add-on accessories or separate oversized cuffs.