Amazon does some sneaky tracking, so I'm not sure if you need these guys as the referrer
but might as well help them (that's how I found this deal. Not affiliated).
Ultimately it leads here:
Choices are black and silver, 0.5 and 0.7, but only the black 0.5 has this price.
And ... Amazon being Amazon : who knows how long the price lasts. I'm in for one, due to weak impulse control