Return air filter rack plenum,for filter 24x20x1" , and round collar , HVAC

This is a  Sheet Metal return air filter rack plenum for filter 24 x 20 x 1". Made in America by hand , housing 26 Gauge . There is a 3/4" hem flange on one 24"x20" end Outside the plenum (around the flange) has dimensions 25-3/4 x 21-3/4" and height 5-1/8", and the other side is fitted with an end cap with a 18" diameter  collar  . Actual overall dimensions flange side for this rack 25-3/4" x 21-3/4" .  From top to bottom the plenum is 5-1/8" long and the collar measures 4" in length. There is a sliding door on the 20" side for filter access. The door can slide from ether side allowing for easy access. Filter for this plenum is 24 x 20 x 1". Filter is not included. We are a complete sheet metal shop. Our prices are fair and our quality is unmatched.