One week ago, Apple CEO Tim Cook mentioned to investors that he finds virtual reality "really cool" and believes it won't remain "a niche." And now a week later, a lot of people are noticing that Apple actually sells a virtual-reality headset on its website.

"[Virtual reality] has some interesting applications."

The headset comes from View-Master, which has transformed its classic red image viewer into a big red VR viewer akin to Google Cardboard. It's essentially just a big plastic case that you slip an iPhone into; you then open up an app that shows 360-degree videos, and you can look around the world by holding the viewer to your eyes and turning your head. It's a super low-tech way of getting into virtual reality, but it's incredibly accessible. As long as you already own an iPhone, you can buy this cheap accessory and get started. Apple is selling it for $29.95 (but you should probably not buy it from Apple because it's much cheaper elsewhere).

You can't make too much of the fact that Apple is selling a third-party VR viewer on its website; it sells a lot of third-party accessories, including some product types that it doesn't formally show support for. The product also came out last fall — before Cook's comments on VR — and Apple appears to have begun selling it back then. But VR is something that Apple likely wants to get involved in, and supporting cheap viewers like this one may encourage other accessory and content creators to get in on the action. Apple may be planning something much bigger for down the road — for now, at least, this is one of the cheapest ways an iPhone owner can get started.

Correction February 5th, 7:50PM ET: Apple began selling View-Master's VR headset a few months ago, not this week as this story initially stated.