Magamp was one of the first slow release fertilizers on the market. I have not seen it in years. Its been replaced by Osmocote and Nutricote fertilizers which work the same way but with a much expanded line of ratios and lifespans. Magamps 7-40-6 ratio is hard to find in a slow release product, most growers got away from high P because it causes uncontrolled leggy growth.. Bob.