The Iron Gym, a leverage-mount pullup bar, is promoted as a total upper-body workout solution. In addition to pullups, you can also use it for doing dips, crunches and pushups. Although the Iron Gym is extremely useful for doing pullups, its performance on other exercises is limited; and, in the case of crunches and pushups, the Iron Gym isn't actually necessary at all.
The Iron Gym's primary purpose is also its best performance. The shorter bar slips through a doorway and rests on top of the trim on the other side, allowing you to mount the Iron Gym for doing pullups with no hardware or drilling required. Although the Iron Gym won't work in every doorway, it is compatible with the majority between 24 and 32 inches wide.
Con: Some Marking Possible
If you use the Iron Gym frequently in the same doorway, over time the short stabilizer bar that rests on top of the door trim may eventually scuff the paint. Yet this is far better than drilling holes in the doorway and can be easily painted over.
As of April 2011, the Iron Gym is readily available for $30 or less --- a reasonable price for a leverage-mount pullup bar, although some of the more expensive options, including an "Extreme Edition" of the Iron Gym that normally retails for about $60, allow additional pullup grip possibilities.
Con: Wide-Grip Problems
The Iron Gym's efficacy as a pullup bar is reduced if your doorway is either too wide for you to grasp the horizontal pullup handle on the outside of the doorway, or too narrow for you to grasp the handle inside the doorway. The "Extreme Edition" solves this problem by adding an additional wide-grip pullup bar. However, you can still use the regular Iron Gym edition for wide-grip pullups if your doorway allows, or for palms-in chinups and neutral-grip pullups.
Pro: Pushup Handles
Although you don't actually need an Iron Gym to do pushups, using its handles allows you to keep your wrists in a neutral position, reducing the discomfort that sometimes arises from the wrist hyperextension of doing pushups with your hands flat on the floor.
Con: Limited Range of Motion
You can also use the Iron Gym as a base for doing dips. Place the Iron Gym on the floor, curved side up, and sit facing away from it. Rest your hands on the arched, parallel bars and press up to lift your hips off the floor, then bend your arms to lower yourself back to the bar. This does work your triceps, but the range of motion is extremely limited and you only lift a portion of your body weight.