M&M METAL MBX-6078 RGSTR BOX 8X4X5 R6 INSUL 4" TALL W/ SNAP RAIL FLANGE #641

Standard size #641R6 register boxes are lined with 1-1/2 in duct liner to provide an R-Factor of R-6. The #641R6 register box is 4 in H with snap rail flange.