Will it fit large smart phones like an iPhone 6 Plus with an slim case, or a Samsung Galaxy / Note / Edge with a Speck case?

 Absolutely, the trend is that people are buying larger and larger phones and we've made sure it will accomodate them. Basically any of the large new smart phones will fit in the main pouch of the Running Belt Max, and you’ll still have enough room to plug in your headphones and listen to your favorite music while doing your activities. It will hold a Samsung Galaxy S4, S5, Note 4, iPhone 6 Plus, and even the 6.3” Samsung Mega and the Sony Xyperia Z Ultra with no problems and even with a bit of room to spare.