The jungle gym system is a tubular nylon strap with handles and foot loops on each end for field expedient exercise. You can do numerous types of exercise and the great thing is that its all hard. Total core stabilization is required to do anything with this so it is core training at its finest. The army has started to purchase a more expensive but identical system called the TRX which runs for about 200.00. It has tactical colors and a bag full of neat bells and whistles. But it basically is the same exact thing as the jungle gym without the name brand label. The jungle gym goes for about 50.00 and it comes with a DVD showing you how to kick your own ass with it. So whether you go with expensive and name brand or the no name economy model, both systems are awesome and extremely effective. You can do almost anything with these systems.
And they are super portable for travel, attached to a door, tree limb, playground, Humvee, Tank, staircase, squat rack, etc... Just throw it in your bag or ruck and move out sharply. Those of you who have already tried it out, you know the power of the dark side. - Because you gotta use the force Luke, just to keep your ass in the air.
Jungle Gym: http://www.monkeybargym.com/cart/index.php?main_page=product_info&cPath=26&products_id=14&zenid=f339947844e918dff240ce56d4992c48
Here is the jungle gym kicking my butt at the home studio - enjoy!!!