It will not allow GFCI to reset if wired incorrectly.
End of life function stops voltage in the event of a GFCI component failure. - See more at: http://products.hardwareandtools.com/af_lighting_bt273073_602570_20amp_duplex_gfci_recept_white_500208228.php#sthash.KwUlNaAL.dpuf
20 Amp/125 Volt AC. 8 back wiring holes and side wire screws accept up to 12 gauge wire