Features: Replacement headgear for use with the Rio II Nasal Pillow Interface system by 3B Medical. The ergonomic and simplistic design of the Rio Nasal Pillow headgear makes adjusting a breeze. There are only 2 Velcro fasters in the front and split back strap that allows quick adjustments. The Rio II headgear is a single size and is made from breathable fabric that does stretch for movement. Once you properly fit the headgear, it can easily be slipped on and off your head without having to further adjust making it one of the simplest CPAP mask to use.