Apple's latest environmentally friendly endeavor will put more sustainably made metal in its new iPhone SE models.

The aluminum, which is used in the metal frame around the sides of the iPhone SE, comes from a new process developed thanks to funds from Apple's planned $4.7 billion Green Bond project, which invests in various renewable initiatives. The novel process reduces the amount of carbon produced when smelting aluminum at an industrial scale that hadn't been previously feasible, according to a press release Thursday.

It's not clear whether this aluminum is in every iPhone SE, which Apple started selling on March 18, or if it will be included in units produced at some point in the future. Apple didn't clarify by press time, nor did it confirm if this aluminum would be used in other iPhones.

Read more: iPhone SE Drop Test: See How Much Damage the 'Toughest Glass' Can Take

While Apple has previously worked to include more recycled materials in its packaging, other phone makers have gone farther. Samsung expanded from using recycled ocean plastic in its packaging to using recycled materials in a few parts of its Samsung Galaxy S22 phones.  

Apple has touted the many projects it's helped fund as part of its Green Bond spend, saying the collected efforts have avoided 921,000 metric tons of annual carbon emissions and generated 1.2 gigawatts of renewable energy, according to a press release. 

But the company has other renewable investments, including a Texas-based research lab exploring better ways to recycle smartphones, increasing the number of parts suppliers that run entirely on clean energy and a goal to make the entire company carbon neutral by 2030.