Transform your doorway into a pull up bar.  Our innovative design is durable, travel-friendly, and gives you the freedom to do pull-ups, push-ups or sit-ups anywhere. It requires no assembly and is ready to use in 15 seconds.  CrossGrips fits door frames that have a top door molding that is 2 to 4 inches tall, and inside door frame that is 4.5 to 7.5 inches wide.