Microsoft has built a universal hardware keyboard for the three operating systems that have large global market share: iOS, Android, and Windows. The new piece of metal, called the ‘Universal Mobile Keyboard,’ will be available in October.

The device marks the continuance of the company’s cross-platform efforts, but in something of a new way: The keyboard is hardware, made for all, and is not a software iteration of an extant Microsoft product brought to a rival platform. That’s to say it is slightly different to build a keyboard that can pair with an iPad, than it is to bring Office to Android tablets, as the company is also doing.

The Bluetooth-capable keyboard can pair with three devices and has a tool to let users quickly switch between their various operating systems. A home key has been included that works across device class.

So why in the name of gracious god is Microsoft doing this? The answer is actually pretty simple: If you want to sell Office across every operating system and platform, you had best ensure that there is hardware in place to make the use of your software functional — so, if you have Office on your iPad, but no good keyboard option, the code won’t be that useful. And that lowers the potential for Office to drive revenue.

Enter the $79.95 device. What are the three operating systems where Microsoft wants to service with Office 365? Android, iOS, and Windows. The same operating systems that the new keyboard works with. As far as mysteries go, this isn’t a very big one.

I’m going to see if I can get my hands on one of the devices for a test. The keyboard attachments that Surface has long strapped into have improved over the life of that product line. It will be interesting to see how much of that has been employed in the new Universal device.

Kicker: The keyboard does not have a touch pad. Something to consider.