HYDROFARM XTRASUN 600WATT 120/240 VOLT HPS BALLAST
Designed in America, employing features and materials normally found on higher priced units, these have become the most popular value-priced units on the market. Their unique patented aluminum housing with convection cooling runs so cool they offer a 5 year warranty - the longest in its class.
Xtra versatile ... works with most fixtures
5 year warranty on ballast electrical components
Aluminum fins, louvers and ports for extra cooling efficiency
Compatible with all Hydrofarm reflectors and most others
Size:5.5"H X 7.75"W X 13"L
They're selling for $150 and up on ebay. Yours for 25 BTC (~$125), shipping included!!