Tesla CEO is teasing a major new product announcement that's coming next month — and it's not a car. Musk just tweeted that his company will unveil a new product line at Tesla's Hawthorne Design Studio on April 30th, with the mysterious reveal scheduled for 8PM PT.

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

Musk hasn't offered any other hints of what's to come today, but last month he said Tesla was nearing the launch of a stationary battery pack designed to power an entire home. Musk said the unit would be ready for a public debut within months, so April 30th could be the day we discover Tesla's vision for pumping electricity throughout your house. Utility companies are already well aware of Musk's ambitions. But this is Tesla and Elon Musk we're talking about, so the chance of a different, unforeseen surprise is always there.