This magnesium gives you two forms of well-absorbed chelated magnesium - bisglycinate and malate - both in high quality, patented versions. It’s a vegan supplement. Whilst a bottle only lasts a month, it’s also worth bearing in mind that the price is substantially lower than the alternatives in our list. 
Why isn’t it higher up our recommended list? It lacks the partner nutrients that can improve magnesium absorption and work with it once it’s absorbed. With bamboo extract as a filler, it’s not an entirely additive free supplement.