I got this from my uncle's friend too. It's a 24V unit designed to be used with a solor panel set up. He gave me a 120V-24V adapter for it so i can run it though. 8-) I haven't wired it up to light it yet though.
thanks! Yeah i tested it and it is bright! On the bluish side too. It's probably 70-100W HPS equivalent. MAybe as many lumens as the 50W HPS but it appears brighter since it's a white light source.