Attributes . Rugged welded design does not fall apart during construction.; Available from one to six gang configurations in both 2-1/2" and 3-1/2" depths.; Rectangular shape fits square cuts in block.; Large volume design allows for additional work room inside the box.; Standard 1/2" and 3/4" concentric knockouts.; Device ears inside the box prevent mortar from getting in the device holes.; Steel voltage partition #971 fits all 2-1/2" or 3-1/2" depths.; Standard wall plates can be used.; Device ears are formed inside the box; Rectangular shape neatly fits square cuts in concrete block, 3-3/4 in. x 3-25/32 in; 31.8 cu. in. capacity; UL listed . Names