LG 26 Sleeve and Stamped Aluminum AXSVA4 Rear Grille for Through-The-Wall Air Conditioners, White/Silver Metallic 26-inch wall sleeve (AXSVA1) and stamped aluminum rear grille (AXRGALA01) for through-the-wall air conditioners Install wall sleeve in pre-cast concrete or masonary walls - wall sleeve to be securely fastened to wall opening before installing air conditioner as it helps bear the weight of the air conditioner Wall sleeve helps insulate the air conditioner and protects it from dust, bugs and other debris that could get sucked into it Wall sleeve's all metal construction withstands inclement weather, corrosion and other elements Stamped aluminum rear grille prevents damage to the back outer coils of unit and prevents birds and small animals from nesting in the wall sleeve