The SteriPEN FitsAll Filter (FAF-ADP) allows you to remove particulates from water with the use of a durable 4 micron screen. It is recommended that particulates be removed prior to treating water with a SteriPEN UV purifier. The FitsAll Filter's unique design offers flexibility to filter water into bottles with a wide range of mouth sizes. Water can be poured through the FitsAll Filter or you can submerge the combined FitsAll Filter and bottle of choice. The SteriPEN FitsAll Filter cup and funnel fit into narrow-mouth bottles such as commercial water bottles, soft-drink bottles, canteens and SIGG bottles. On wider-mouth bottles, such as Klean Kanteen, Gatorade and Nalgene bottles, only the cup is necessary. The FitsAll Filter cup also serves as an adapter that allows the SteriPEN Journey or Classic to be used with these wide-mouth water bottles in the inverted position. Weighing only 65 g (2.3 oz.), the FitsAll Filter is made with rugged, flexible materials that allow the filter to be squeezed during storage and return to shape when unpacked. Nested storage dimensions are 88mm (3.5 in.) x 95mm (3.7 in.) x 72mm (2.8 in.).