This is a Dirt Dog subsoil ripper that can go up to 25.5" deep and fits a cat 1 hitch on a 25-45 hp tractor. There is also a pipe laying attachment that will handle up to 2" poly pipe. I bought this setup new and used it once to lay a water line. I paid $473.08 for the pair and am asking half price. Cash only. Here is a couple links to the subsoiler:
http://www.sweettractors.com/New_Dirt_Dog_1_Shank_Subsoiler_p/dirtdog1shank.zone.3.htm
http://dirtdogmfg.com/categories/1/products/31/Sub-Soiler

Here is a link to the pipe layer:
http://www.agrisupply.com/point-pipelayer-attachment-fits-single-tine-ripper/p/73622/&sid=&eid=/