The NB 577 Walkers fit well but the Velcro straps are more narrow and most importantly much shorter.  I haven't worn the walkers yet and am concerned that the straps might not hold in the future. As you can see in the photo, my older New Balance 575 Walkers have a wider, longer strap.  Update.  I've been wearing my Walkers and they are super comfy and supportive. I pull the Velcro straps tightly and so far they have held. At only $26.19, they're worth the challenge.