One Model 350 Dryerbox^® - 22 Ga. metal deep drawn recessed dryer vent box with gas port, measures 3 1/2 inches deep from nailing flange. For 2x4 construction but has a very oval shaped port on top to accommodate the squished 4" Snaplock pipe.   

22 gauge aluminized steel weighing 4.03 pounds each

Top port measures 4 7/8" x 3 1/8" oval shape

Distance from nailing flange to rear of box is 3 1/2"

Overall measurements: 21" h x 12 1/2" w x 4 3/8" deep

Inside measures 9 1/2" wide x 18 1/4" tall

Can be installed upside-down for dryers on a pedestal or stacked
 

Links: Drawings/Measurements  -  Instructions

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