Major new Tesla product line — not a car — will be unveiled at our Hawthorne Design Studio on Thurs 8pm, April 30

— Elon Musk (@elonmusk) March 30, 2015

What could the product be? A Tesla executive said last month said the electric car company is working on battery technology that could power a home or office, potentially taking lessons it has learned in battery design and using them to open up new revenue streams.

But it’s also worth noting that “not a car” isn’t the same thing as “not a vehicle.” There have been rumors for years that Tesla could make an electric motorcycle, truck or van, though the company has yet to release the electric SUV or cheaper sedan models it has already announced.

Twitter users, of course, have had their fun guessing what it could be with the #TeslaNewProductGuesses hashtag:

Space elevator?
Tachyon beam?
Flux capacitor?#TeslaNewProductGuesses

— Alex Rubalcava (@AlexRubalcava) March 30, 2015

https://twitter.com/ivanhoff/status/582586060875505665

Something I can't afford! #TeslaNewProductGuesses

— Jason (Agent Palmer) Stershic (@AgentPalmer) March 30, 2015

Hoverboards #TeslaNewProductGuesses

— Anthony Quintano (@AnthonyQuintano) March 30, 2015

And Musk himself has been known to tease Tesla news on Twitter:

About time to unveil the D and something else pic.twitter.com/qp23yi59i6

— Elon Musk (@elonmusk) October 2, 2014

Tesla reported disappointing earnings last quarter, losing 13 cents per share on adjusted revenue of $1.1 billion.