In addition to the usual spec bumps and new bands, Apple had another announcement to make at the launch of its Series 9 Watch: The new model is its first carbon neutral product.

Here’s how that works. First up is electricity. All Watch manufacturing is now powered by “100% clean electricity,” which probably means a mix of renewables plus nuclear and hydropower. The company also took the unusual step of buying renewable power on behalf of consumers. Apple forecasts how much electricity will be required to charge the watch over its lifetime and invests enough in renewable energy projects to offset that figure.

Next is recycled materials. Aluminum for the cases; tin, gold, copper, and tungsten for the various chips and connections; and cobalt for the battery. The sport loop, which Apple says is one of its most popular, now contains 82% recycled yarn. Leather bands? They’re out.Shipping is another factor in carbon emissions. The new Series 9 packaging is 100% fiber based and smaller, letting Apple ship 25% more watches per trip. The company is also sending more via cargo ships, which are far more efficient than planes.

Together, those efforts reduced the carbon footprint of Apple Watch by 78%, said Lisa Jackson, the company’s vice president of environment, policy and social initiatives. To eliminate the rest, she said it will buy offsets in the form of credits from forests and wetlands.