FeaturesRevolutionary patented design expands from 2 to 3-1/2 in for while-in-use needsHeavy duty die-cast metal constructionPatented Quick-Fitâ„¢ keyhole mounting system allows installation in under a minutePre-configured for GFCI with patented Knock-Outâ„¢ technology for alternate devicesLockable open or closed and fits full size padlockPatented swivel locking device