Lenovo, the world’s biggest PC manufacturer, is also a maker of among the smallest.

How small is it?

“Is that a computer on your keychain?” So tweeted Microsoft.

It’s about the size of a thumb drive.

Tom Thumb goes digital … powered by an Itel Atom processor.

On Tuesday, Lenovo unveiled its Ideacentre Stick 300, a device small enough to fit on a keychain but powerful enough to turn devices such as TVs into computers.

The Stick also comes equipped with Windows software.

Lenovo is diversifying beyond PCs with smartphones, tablets, servers and more. But it also is seeking to capitalize on the “Internet of Things ‘ – the growing global trend of Internet-connected devices – and the Stick is taking the Lenovo brand to more devices than ever.

It sells for $129.

Lenovo’s not the first to offer a PC on a stick. But it does ship with Windows 8.1 software and is upgradable to Windows 10 as of July 29.

Of course, you need more than the Stick to turn that HD TV into a PC.

“Paired with a 2.4GHz keyboard and mouse, the new Lenov Ideacentre Stick 300 transforms any monitor into a PC, supporting a web-enabled, Windows ready work or entertainment station,” Lenovo notes.

“We’ve looked at the computing needs of travelers, business people and families, and realized that a truly portable and affordable solution would be a significant benefit to users of all kinds,” said Jun Ouyang, vice president and general manager of Worldwide Desktop and Visuals for Lenovo. “Our goal with the ideacentre™ Stick 300 is to give those users a sense of freedom and enhanced mobility, while packing a serious punch in a small device.”

Notes Microsoft:

“The Ideacentre Stick 300 expands the mobile computing experience and options for savvy shoppers and is suitable for use in the home, dorm or office, while simultaneously offering portability and convenience for travelers. For the wallet friendly starting price of US $129, this plug and play technology can transform almost any HDMI compatible TV or monitor into a fully functioning Windows-based PC.”

The Sticks go on sale shortly at Lenovo.com and will hit retail store shelves in October.

Lenovo operates its global executive headquarters in Morrisville.