I ordered these!
http://www.amazon.com/3M-Respirator-..._bxgy_hi_img_y

I changed out the large filter's for these filters. These were on all the welding supply sites and are for galvanized. I had to cut my cheapo hood to get the larger filters to fit, but these fit under my other helmets.
http://www.amazon.com/gp/product/B00...?ie=UTF8&psc=1