The second stage or intermeditate catch bag is filled with natural rock gravel and a small mix of chinese herbs. As the practitioner uses the bag, the herbs break down and pass through the canvas into the hands. 
 
Natural rock gravel has the correct consistency and hardness  needed to develop through the second stage of this program. In addition, rock will also break down giving you a measure of where you are on your training, The natural minerals of the rock are also helpful to develop the resisteance of the skin.  The additional herbs move Qi and blood to prevent bruising and have antiseptic properties. Although not recommended, the bag can be used in the abscence of Dit Da Jow. 
 
The bag is 5'' X 5'', hand constructed using heavy cotton canvas. It weighs 0.75 to 1.0 pounds. The foucs of training with this bag is not on gaining strenght but rather on focusing the strike and grip of the bag as it is in motion. Its size allows it to be used by anyone, male or female, youth or adult, large or small. 
 
How to use:
 
For solo practice: form a horse stance, swing the arm up throwing the bag vertically and  strike and grip as the bag is coming down. First with the same side, changing sides after a certian number of repetitions, A variation of is to throw with one side and catch withthe opposite side. 
 
With 1 or more partners: Throw the bag towards you partner, they catch and throw back to you. With more participants the bag can be thrown to anyoone, randomly. More than one bag can be used at the same time. 
 
Note: The use of a quality Dit Da Jow liniment is highly recommended for all types of Iron Palm/Iron Body/Iron Skills training. This bag is more forgiving given its mediicinal filling, so the occassional practice without Dit Da Jow is ok, however, for best results, always use Dit Da Jow.