We know a pretty decent amount about the Tesla Model 3 so far, but until just recently we didn’t know a ton about what kind of batteries those cars will pack out of the gate. Now we do! Elon Musk let it slip during a conference call that the new electric sport sedan comes in 50 kWh and 75 kWh flavors.

That news comes to us from Electrek, which has been reporting that Tesla’s less focused on the battery naming scheme for the more mainstream Model 3 and more on its actual range instead in order to appeal to a wider audience. Which is fair—for a lot of people, 50 kWh, 75 kWh and 100 kWh probably don’t mean a ton yet, except for the obvious fact that bigger is better and faster.

The news site says Musk revealed during a conference call hosted by Goldman Sachs for bondholders that the Model 3 will have a pack just over 50 kWh with a range of about 220 miles, and a “long-range” version with a 75 kWh pack good for about 310 miles. That larger battery is expected to cost about $9,000 more.

Why, besides range, does this matter? Because it has wider implications for investors:

The information is especially important to investors who are attempting to estimate the cost of the Model 3 in an attempt to model ways that Tesla can achieve its targeted 25% gross margin on the vehicle.

For example, at $150 per kWh, the Model 3 battery packs would cost between $7,500 and $11,250 per vehicle. A few dollar difference per kWh or a few kWh difference per battery capacity can make a significant overall impact on the cost of the electric car.

Tesla had previously disclosed that its battery pack cost was “below 190$ per kWh” and they aim for Gigafactory production to reduce the cost by 35%. Musk also said that he would be disappointed if they don’t bring the cost below $100 per kWh by the end of the decade.

At any rate, don’t expect a high-performance Model 3 variant until sometime next year at the earliest (assuming no delays, and you know how this company is with those) and that it won’t get the 100 kWh pack from the larger Model S and Model X due to size constraints.