Thomas & Betts 223-TB Conduit Bushing Brand: Thomas & Betts. Part Number: 223-TB. T&B Conduit Bushing, Non-Metallic, 3/4 in, Insulated Insulated/Non-Insulated, 105 deg C, Plastic, 1-9/32 in Dia x 13/32 in H. Additional Description: TB -223-TB 3/4 PLASTIC INSUL. BUSHING. Catalog Description: 3/4 Inch Non Metallic Insulated Bushing for Use with Rigid/IMC Conduit..