Source Naturals Mag Active Quick Absorption Magnesium -- 8 fl oz

What the brand says

Magnesium supports the heart, bones, and muscles, and plays a part in energy generation and in the immune, endocrine, and nervous systems. Source Naturals Mag Active is a purified liquid concentrate on activated ionic magnesium, in a broad spectrum of many other essential and trace minerals. Mag Active is naturally derived from the Great Salt Lake and has had 99% of the sodium removed.