Construction for recess in plaster wall

Claim 1

A PREFABRICATED CONSTRUCTION FOR A RECESS IN A PLASTER WALL, SAID CONSTRUCTION COMPRISING: CASING MEANS DEFINING THE SIDE WALLS OF SAID RECESS; SAID CASING MEANS HAVING A PAIR OF OPPOSITE OPEN ENDS; IMPERFORATE LIP MEANS EXTENDING OUTWARDLY AT ONE END OF SAID CASING MEANS AROUND THE PERIPHERY OF AND SUBSTANTIALLY PERPENDICULAR TO THE CASING MEANS; FLANGE MEANS EXTENDING OUTWARDLY AT THE OTHER END OF THE CASING MEANS AROUND THE PERIPHERY OF AND SUBSTANTIALLY PERPENDICULAR TO THE CASING MEANS; SAID FLANGE MEANS AND SAID LIP MEANS LYING IN RESPECTIVE SUBSTANTIALLY PARALLEL, SPACED-APART PLANES; SAID FLANGE MEANS EXTENDING FURTHER OUTWARDLY THAN SAID LIP MEANS; SAID FLANGE MEANS BEING IMPERFORATE IN THE AREA OF PROJECTION OF SAID LIP MEANS ON THE FLANGE MEANS, WHEN THE LIP MEANS ARE PROJECTED IN A DIRECTION PERPENDICULAT TO SAID FLANGE MEANS; SAID FLANGE MEANS INCLUDING, AS AN INTEGRAL PART THEREOF, EXPANDED MATERIAL MEANS EXTENDING OUTWARDLY AROUND THE PERIPHERY OF SAID IMPERFORATE AREA; AND A PLURALITY OF OPENINGS IN SAID FLANGE MEANS; ALL OF SAID OPENINGS BEING LOCATED OUTWARDLY OF SAID AREA OF PROJECTION OF THE LIP MEANS ON THE FLANGE MEANS.