Samsung offers free Gear VR headset for everyone who buys a Galaxy smartphone before June 19 - GSMArena blog
Amazon.com: VR Headset Virtual Reality Headset 3D Glasses with 120°FOV, Anti-Blue-Light Lenses, Stereo Headset, for All Smartphones with Length Below 6.3 inch Such as iPhone & Samsung HTC HP LG etc. :
The Galaxy Note 9 works with Gear VR via free adapter - CNET