This high back lavatory support is engineered for through installation on block walls. Threaded sleeves are welded to a heavy gauge steel plate mounted to the side of the block wall opposite to where the lavatory will be installed. The sleeves accept the threaded arms that will support the lavatory. Lock nuts spin along the threaded arms from the lavatory side of the wall to tightly sandwich the wall and level the arms. To ensure that the lavatory is permanently and solidly affixed to the support arms, our Sure-set locking device easily adjusts from underneath the lavatory to firmly grip its inner wall while leveling screws ensure a precise installation.