surface and a top surface the dry stack unit also has a rear section substantially parallel to the front section having an outer surface an inner surface a bottom surface and a top surface two or more webs coupling the inner surface of the front section to the inner surface of the rear section have a top surface and a bottom surface two or more pairs of lugs may extend above the top surface of the front section and the top surface of the rear section each pair of lugs may have a first lug offset from a second lug in an axis perpendicular to the inner surfaces of the front section and the back section application_number US 25556505 A description a corner wall structure 200 may use a stretcher unit 202 and a corner unit 204 to construct the corner and straight portions of a wall as shown in fig2 the stretcher units 202 have lugs 206 that extend above the top of the stretcher unit 202 the next course of stretcher units is placed on top of the previous layer of stretcher units the lugs 206 of the previous layer of stretcher units extend into the cells of the next course of stretcher units the lugs provide face shell alignment lateral strength and lock together successive layers of units the stretcher units 202 have a front section and a rear section one or more webs or ribs couple the front section to the rear section the one or more webs may extend just below the top surface of the stretcher unit 202 or may extend all the way to the top surface of the stretcher unit 202 the stretcher units 202 also have lugs that extend above the top surface of the stretcher unit 202 the stretcher.