Comparison : Item # 1031-5406-04-02, 1/4"-18 MPT x 1/8"-27 FPT Steel MP-FP Reducer Bushing
Item # 1031-5406-04-02-B, 1/4"-18 MPT x 1/8"-27 FPT Brass MP-FP Reducer Bushing
Item # 1031-5406-04-02-SS, 1/4"-18 MPT x 1/8"-27 FPT Stainless Steel MP-FP Reducer Bushing
Item # 1031-5406-06-02, 3/8"-18 MPT x 1/8"-27 FPT Steel MP-FP Reducer Bushing
Item # 1031-5406-06-02-B, 3/8"-18 MPT x 1/8"-27 FPT Brass MP-FP Reducer Bushing