The Supreme Court on Wednesday preserved a key Biden-era regulation that treats “readily convertible” gun kits, which are commonly referred to as “ghost guns,” as firearms under federal law.

Justice Neil Gorsuch, writing for the 7-2 majority, concluded that the Bureau of Alcohol, Tobacco, Firearms, and Explosives acted within its authority when it issued a 2022 rule clarifying that gun control laws apply to kits that can be easily assembled into functioning firearms that are difficult to trace.