The 4" Febco LF850 Series began production in 2010 and was introduced to replace the original 850 models. The LF850 is the lead free version to meet new nation wide codes. Known as the "Master Series" the LF850 is constructed of epoxy coated ductile iron with bronze check assemblies. Checks are a swing check type with self contained spring modules. Check seats are replaceable. Check discs are vulcanized rubber disc type. No special tools are required for servicing.