We built them.
Why aluminum tubeless valve stems? Well, it turns out that not everyone needs the added strength (or let's be honest, cost) of our titanium valve stems. So took much of what makes our Ti stems special and applied it to the lighter metal.
But why stop there?
Seeing as no one needs another disposable product, we wanted to keep our our tubless valve stems in service as long as possible. So we made the parts that wear or which can be fouled by sealant easily replaceable.