Featuring an all welded construction and sealing plastic ring, the Eaton SENTINEL filter bag is made to prevent bypass for reliable filtration. Eaton bag NMO-100-P04E-E-50is a 100 micron rated filter bag made for size 04 filter housings. Eaton's SENTINEL bags are constructed using welded seams as opposed to sewn. This makes for a stronger seam and eliminates needle holes which can allow bypass. This SENTINEL bag comes with a Polypropylene ring. The bag itself is Nylon monofilament. This bag comes 50 per box.