Enpac Boss filter bags rely on the innovative new design and high quality filter material for removing sediment from discharge pump water. Features include a round neck opening (up to 4-inches) with a web strap closure. The filter bag is formed from non-woven, polypropylene geo textile material made for removing oil, grease, sediment, litter and debris from pump water. The Boss filter bag is an inexpensive and easy-to-use Best Management Practice (BMP), that will help you comply with NPDES, EPA 40 CFR 122.26 Stormwater regulations. Regulations: NPDES, EPA 40 CFR 122.26. Measures 36-inches length by 36-inches width. 500 GPM capabilities.