after use this dust bag for month now , I be pleasantly surprise at how much dust the bag actually collect . in fact , it work better than I think it would . the capacity be quite good and you can use the saw quite a bit before have to empty the bag . do the bag collect as much as a shop vac attach to the saw or a dust collection system ? of course not , and it would be unreasonable to expect that it would . I be puzzle at some review that knock the product for not compare favorably to a true dust collection system . I use the bag on a Bosch 4100-09 unit and use both the stock and zero clearance insert . contrary to some reviewer , I have not find the bag to significantly restrict output airflow . at home I use a dust collection system , but on the road this bag work well and save cleanup time at the end of the job . I think if you keep you expectation reasonable , you will be satisfy with this dust bag .