Keystone KSTSLV1 Wall Sleeve for Through-The-Wall Air Conditioners, 26" 26-Inch wall sleeve to be used with through-the-wall air conditioners.Protects the air conditioner from dust, bugs and other debris that could get sucked into it Install wall sleeve in pre-cast concrete or masonry walls Wall sleeve to be securely fastened to wall opening before installing air Conditioner All metal construction withstands inclement weather, corrosion and other elements Compatible with: kstat08-1c, kstat10-1c, kstat10-2c, kstat12-1c and kstat12-2c