Apple‘s big news this afternoon? The Apple Watch Series 10 can now be entirely carbon neutral—assuming you pick the right band. Apple’s making a push to reduce its carbon footprint, but there’s a catch: carbon neutrality only applies when you pair your watch with specific bands.

Here’s the lowdown: the Series 10 comes in two flavors—aluminum and titanium. Both options get the green stamp of approval when you choose a Sport Loop band, a Braided Solo Loop, or the updated Milanese Loop. So, if you’re gunning for the full carbon-neutral experience, those are the bands to go for.

What’s making this possible? Apple is using either 100% recycled aluminum or 95% recycled titanium for the watch cases. They’re also doing their part by buying enough renewable energy to cover the electricity used in manufacturing each watch. And, in a bid to keep things eco-friendly, they’re minimizing air shipping to cut down on transportation pollution.

Last year, Apple rolled out its first carbon-neutral products, which included select case and band combos from the Series 9, Apple Watch Ultra 2, and Apple Watch SE. But today’s announcement takes things up a notch by expanding the carbon-neutral range to include the new Series 10 with those specific bands.

Now, let’s talk about what “carbon neutral” actually means. To be called carbon neutral, Apple is offsetting the remaining CO2 emissions by investing in high-quality carbon credits from nature-based projects. These projects usually involve planting trees or restoring forests that naturally absorb CO2. However, it’s worth noting that not all carbon offset projects are created equal—some have been criticized for not delivering on their promises.

This is why it’s crucial to not just look at individual products but at a company’s overall carbon footprint. Even if Apple is making strides with its watches, if the company’s overall emissions are rising due to more frequent gadget releases or planned obsolescence, it could negate some of these gains.