The Armstrong SBA contain an interchangeable module that consists of a stainless steel pump shaft and a housing that contains precision crafted front and back end bearings that are permanently lubricated. safer solution for facility and service personnel. Faster on site service and replacementS&H #4 Series Maintenance-free Seal Bearing Assembly, a longer circulator life without maintenance regular oil lubrication is not requiredno more oil pools on floorStainless steel face plate, coupler face guard meets or exceeds OSHA standardsThe standard for 65 years in hydronicsRepairable, replaceable, environmentally friendly and now maintenance free. WARNING Cancer & Reproductive harm www.P65Warnings.ca.gov