Pondmaster Small Pre Filter Replacement cylinder foam for Mag Drive Pumps. These pre filters trap large unwanted particles before they can clog up and potentially damage the pump filter.
Part# 12505
Fits:
Mag Pumps 2, 3, 5, and 7 
Mag Drives 250-700 models
Dimensions: 4"L x 2.25"W x 1"ID