Does anyone have or know of the below poultry pen/tractor. I found on-line through craigslist someone who is selling all their chicken supplies as they are moving and thought this would be good for my layer hens. Thanks "This premier portable poultry pen of modular design is for raising free-range poultry for meat or farm fresh eggs, while fertilizing your lawn, garden or pasture. Moving the pen to a fresh area each day can insure birds a more natural diet (weeds, grass, and bugs), therefore reducing feed cost and also reduces manure buildup to insure healthier birds and provides the proper amount of fertilizer to your lawn, garden, or pasture. Easy to follow assembly instructions are included. Standard Pen Features 1. Heavy gauge aluminum & zinc plated hardware. 2. Size 5W x 10L x 21H. 3. Two 5x 4 hinged covers; one solid & one ventilated. 4. 10 retractable wheels for easy mobility. 5. Supports 40 Broilers up to 8 weeks or 25 layers. Benefits 1. Protection from predators. 2. Ecologically friendly. 3. Easily sanitized. 4. Will last for years."