Patent-pending design, rugged steel construction similar to standard mud ring but with greater flexibilityQuick release locking mechanism enables fast and easy adjustment of inner ringLocking mechanism located behind outer ring remains safe from router damage or excess muddingAdjustment screws located outside inner ring leaving maximum capacity for devices, won't take up crucial box areaMeasured rule on inner ring for simple pre-fab setting in pre-drywall installationsMounts to any standard 4 in square 2-1/8 in deep outlet box and accepts industry standard devices, including GFCIsFor hospital construction where drywall depth often varies, ceramic tile wallsFor any other application in which a stud-mounted box and mud ring may require depth adjustment prior to final trim workMud Rings feature an inner ring that adjusts from 1/2 in to 1-1/2 in in depth to accommodate various drywall thicknessesDouble gang