Different tours will come on physical "experience reels" (resembling the original circular slides), which don't slot into the headset but can sit on a table, for example, in front of multiple viewers wanting to take the same tour.

The original View-Master.

Technically, the device doesn't need the reels to function (tours can just be downloaded on the app), but Mattel says it decided to make them appeal to nostalgic collectors of the old-timey toys that date back the 1939 New York World's Fair.

The partnership is an attempt to answer a nagging question in the toy industry: How do you make existing products relevant as kids turn away from traditional toys and toward video games for the iPhone and iPad? Mattel thinks it has cracked that nut.

The advantage to Mattel is clear — it hopes to capture kids by offering them the next big thing.