Commercial-grade, Thru-the-wall, Perfect Fit for a 27" Sleeve Whether you're replacing an existing air conditioner or working on a project that requires a more permanent installation, WallMaster is a perfect fit for existing 27" sleeves. Once installed, there is no discernible gap between the unit and the sleeve creating a clean, finished appearance and minimal intrusion of outdoor air. Built with the best commercial-grade materials and components, WallMaster is durable yet quiet. Its solid-side sleeve assures maximum performance in thicker wall applications and gives you multiple installation options. Plus, the Baffle Adapter Kit expands the depth of sleeves that can accommodate WallMaster . Choose from cooling-only, cooling with electric heat or a heat pump. All WallMaster s come with a wireless remote plus convenient top-mount controls, a 24-hour programmable timer, an energy-efficient MoneySaver setting and many other premium features. 2 year parts and 5 year limited sealed system warranty. Components and Construction Fan motors: Robust, commercial-grade and totally enclosed fan motors run at lower temperatures to prevent overheating Non-rusting aluminum endplates: Won't leave rusty condensate collecting in the drain pan and will prevent unsightly rust stains on buildings High-tech, rifled copper tubing and slit fins: Greater surface area creates maximum heat exchange efficiency Heavy 20-gauge steel cabinet: Strong and durable Solid sleeve top: Protects the fan from falling debris that can damage the unit Insulated plenum: Prevents outside air intrusion EntryGard anti-intrusion protection uses a steel retaining wire to secure the chassis to the sleeve Quiet performance High-efficiency compressor: Mounted on large, vibration-absorbing grommets Extra-thick rubber grommets: Absorb motion and sound Motor mount with dual resilient rings: Prevents metal-to-metal contact that can cause noise and vibrationSolid steel blower wheel housing: Provides maximum sound reduction Designed specifically for thicker wall installations Unlike solid-side thru-the-wall air conditioners, window air conditioners have side vents. Covering an air conditioner's side air vents can restrict air flow, diminish performance and potentially void your warranty so we strongly advise against it. Our solid-side sleeve has no side vents. You can install it through walls up to 15 5/16" deep without compromising performance. See the model specifications for specific sleeve measurements. Flexible options WallMaster fits perfectly with any 27"Wx16 "Hx16 "D sleeve, including Friedrich's WSE sleeve and Fedders' A sleeve. It also can be installed in Fedders' 19 " B sleeve with the available Baffle Adapter Kit (BAK, see accessories). The unit can be mounted flush with an exterior wall or closer to the interior wall for a slimmer indoor profile. And the optional architectural grille enhances the unit's exterior appearance.