In their Kickstarter campaign, these were offered as a Titanium version with no tritium slots for $75, or a Tritium version with tubes for $350. As far as I can see they were never offered with empty slots for the user to provide his own tritium vials. Therefore it's pretty safe to assume Massdrop is offering the Titanium version without slots and should update the main photo accordingly.
I can't quote any laws but I do know that tritium is illegal in the US for "frivolous purposes" such as toys and keychains. It is legal for watch dials, gun sights, emergency exit signs and such. It is regulated by the Nuclear Regulatory Commission and there are specific licenses required to import and sell tritium equipped goods.
Like others, I have purchased vials directly from overseas vendors...I'm pretty sure this is a grey area at best...
I can't quote any laws but I do know that tritium is illegal in the US for "frivolous purposes" such as toys and keychains. It is legal for watch dials, gun sights, emergency exit signs and such. It is regulated by the Nuclear Regulatory Commission and there are specific licenses required to import and sell tritium equipped goods.
Like others, I have purchased vials directly from overseas vendors...I'm pretty sure this is a grey area at best...