PEMU-400-P04S-50 Eaton SNAP-RING Filter Bag F3AB00341Made under ISO 9001 standards, SNAP RING filter bags are designed to be reliable and consistant. The bag description for this Eaton SNAP RING filter bag is PEMU 400 P04S 50. That describes a polyester multifilament bag with retention rating of 400 microns. It also denotes that this is a 04 size filter with a carbon steel ring. The ring is sewn into the top of the bag and sits at the top of the filter housing when installed, creating a seal. Part