Ensure proper return air flow for your 21 in Winchester residential electric furnace application with this easy to assemble return air box. The flexible design allows for connection of a new or existing side air return on either side based on the placement of the reinforced sheet metal panel of the return air box assembly. Plus， the knock-down design simplifies transporting to the job by taking up very little space.

Durable 26 gauge sheet metal with knock-down design for ease of handling at and transporting to the job site

Reinforced panel of the return air box assembly ensures sturdy connection of side air return for up-flow applications

Based on the placement of the reinforced panel of the return air box assembly， the return air drop assembly can be mounted on either side for flexibility

Easy to assemble and includes rivets; sheet metal screws， if supplied in the field， may be substituted