The GoFit Pro Gym-in-a-Bag is just the ticket to achieving your fitness goals-whether it's to build size and strength, or increasing muscle definition. The key to the Pro Gym is the ability to add or subtract resistance by adding or subtracting the resistance tubes. There are 3 levels of resistance: light, medium and heavy, and the different colors signify the various levels of resistance allowing you to achieve 7 different levels of resistance, by using different combinations of all 3. Includes 2 handles, 3 resistance tubes, 2 ankle straps, 1 door anchor, instructional DVD, training manual and nylon carry bag for storage or travel. Gender: unisex. Age Group: adult.