This air tool is for mattress spring fix on the spring mat. The tool most of made by steel,  so the weight is not light, but it was durable.  
The tool make nail  looks like a  big U , fix the spring on the spring bed. 
This one have a shelf, it will make the air tool become more light, waist do not feel painful. One roll staple have 10000pieces, it will work more time , no need change the staples always, save time .