Dielectric Union: 1. Zinc Plated Forged Steel 2. EPDM Washer & ABS Insulating Sleeve 3. Sizes range: 1/2" MIP x 1/2" SWT Dielectric Union 3/4" MIP x 3/4" SWT Dielectric Union 3/4" MIP x 1/2" SWT Reducing Dielectric Union 1/2" FIP x 1/2" SWT ~2" MIP x 2" SWT Dielectric Union 1/2" FIP x 1/2" FIP ,3/4"FIP X 3/4" FIP,1"FIP X 1"FIP Dielectric Union