This was an important feature for me. The supported Bluetooth codecs of the PX7 is SBC, AAC and aptX adaptive. I wouldnt pay more than $10 for this walking in the dark demo. Courtesy of a very fast metabolism and athletic lifestyle, I sweat a lot. These are a marvellous addition to my summer wardrobe. Nice slippers, soft and warm. The little bumps wear down. You really need to stretch them to fit, they seem to be a tad smaller and with less foam, so definitely need to massage them to get them on. So if you prefer loud sounds because your deaf like me - I would beware before buying. They do also come with a pair of ear plugs in the box, and the sound quality and volume improves dramatically with these in (or if you stick your fingers in your ears).