1 stainless steel main ball two hole flange carbon steel housing, 2w one inch stainless steel main ball rotates on a bed of eighty 1/8 inch stainless steel support balls. Support cup and cover are hardened and zinc plated carbon steel. Hudson bearings is an innovative domestic manufacturer of ball transfers. flange-mounted units feature a hardened and zinc plated mounting cup and a foam seal. housing options include stainless steel with option for felt seal. main and support ball options include stainless, nylon, phenolic, and delrin. flange mounted transfers can be used in either ball up or down position.