Includes 4 Grommet Sizes - 18, 16, 14, & 12AWG Each unit has a Self-Testing feature meeting UL GFCI Standard Replacement GFCI Plug Unit for Spas, Power Washers, & Many Other Appliances Auto Reset User Attachable - UL943 Listed 15 AMP 120 Volt Rugged Design and Construction. Built to withstand heavy use & is waterproof Detailed Replacement Instructions Included with Each Unit