The iFixit teardown was necessary to find out what Apple’s design changes were because the company refused to actually explain them beyond telling reporters that it had utilized a “new material.” So the teardown commenced, and the results are subtle enough that it has taken special scientific equipment (and will take even more in the future) to determine the difference.

The first of iFixit’s discoveries is that Apple is, in fact, using a new material inside a component of the key inside the keyboard. There’s a polymer over the actual keyboard switch that previously was a complex polymer and now appears to essentially plain old nylon, according to an FITR analysis. Apple began using a silicone membrane inside the keyboard last year. The company insisted it was there to reduce noise, despite patent filings and service documents confirming that they were intended to protect against debris. This new material doesn’t change that overall membrane, but instead this is a second kind of polymer that lies underneath it.

The newer material is “clearer and smooth to the touch,” according to iFixit. Though why the change might help is anybody’s guess. Perhaps it’s better at not allowing dust to get stuck under it? At this point, only Apple really knows for sure.

The second change is even more mysterious. On Apple’s butterfly keyboard, there is a metal dome switch underneath each key. It’s the thing that makes the electrical contact that registers a keypress. Apple appears to have made minor changes to these switches in the new keyboard.

Left: old, 2018 switch. Right: new, 2019 switch.

iFixit says that “The difference in surface finish from the 2018 version (left) to the 2019 (right) indicates Apple may be using a revised heat treatment, or alloy, or possibly both.” However, a full analysis of what’s changed will require much more sophisticated equipment than iFixit currently has access to. Again, it’s a question that Apple could answer at any time.

What does seem clear, however, is that these metal switches are likely the culprits for many (though probably not all) of the keyboard failures people have been experiencing. They’re just tiny and delicate — they work by popping down and pushing back up “like a really tiny jam lid or Snapple cap,” iFixit notes. It’s not hard to imagine the world’s tiniest Snapple lid deforming under the kind of stress all laptop keyboards have to endure.

So it makes sense that Apple would be iterating on this part and trying to make it as resilient as possible — but it’s also surely true that there’s a limit to how effective that strategy could possibly be. As for what could be breaking those switches on current keyboards, theories run from dust to grit to metal fatigue. A very popular Reddit post from earlier this month lays out the case for the latter.

Apple’s butterfly keyboards have undergone several revisions since their debut on the MacBook in 2015, but none have managed to fix the underlying reliability issue. The second generation came with the 2016 MacBook Pro, with a slight update in 2017 to dampen noise. Problems persisted, and the 2018 MacBook Pro came with a third-generation keyboard with silicone membranes. Now, in 2019, the third generation has been tweaked with the new switch cover and switch materials.

Every one of those keyboards sold in the past four years, as well as the new 2019 models, are now covered under a new repair program, and Apple has said repair times for keyboard issues have been shortened as well. It’s up to you to decide whether the more comprehensive repair program should be cause for relief or concern.

It’s impossible to know right now whether the new design detailed by iFixit will solve the reliability problems once and for all. What we can say for sure is that the fundamental design of the butterfly keyboard hasn’t changed. That means that when one breaks — even if that happens more rarely now — it will require an intensive repair.

At the end of the day, Apple’s butterfly keyboard has a much bigger flaw, one that this model’s tweaks cannot fix: too many people have simply lost faith in this design. Apple could theoretically combat that loss of trust with more candor, but it certainly hasn’t been forthcoming thus far. Getting the company to even admit that there might be a problem has been a years-long process.

When it comes to consumer trust in Apple’s butterfly keyboards, different materials won’t make a material difference.