Description. Replacement EPDM Rubber Impellers for Zambelli Flexible Impeller Pumps T-25, T-40, T-70, T-110, T-180, T-250, & T-500. Standard, single-speed pumps ("FL" & "Export") have an external stainless steel hub that protrudes from the center of the impeller by 1". Variable speed pumps ("VM", "2V", & "ICDR") have an internal stainless steel