Model 350 is designed to accommodate installations that require a shallower stud bay or additional space behind the Dryerbox. This model's depth from the nailing flange to the rear is 3 1/2" and will fit in a 2 X 4 stud bay. It is important to note that Snaplock pipe becomes "ovalized" when drywall is secured to the studs. To handle this compressed state, model 350s have an oval port.