Model No. 20381;One piece box and mounting flange design needs no additional framing or support when installed to the stud bay;Optional mounting by use of the Water-Tite Stabilizer Bar allows the box to be positioned anywhere in the stud bay;Contains integral test cap with rubber gasket for leak testing and protection during the construction phase;Access Box connects to 1-1/2" or 2" ABS or PVC vent pipe;Includes a one-piece snap-on grille;Recess box carries UPC and ICC listings