Hillman #12 - 14 x 3/4 In. Hex Washer Head Self-Drilling Sheet Metal Screw (100 Ct.) Spade Bit Set coated on both sides with

coated on both sides with an aggressive

Concrete & More

0 sones and utilizes a 4 inch round plastic duct collar with backdraft damper which allows the unit to be used to comply with ASHRAE 62

Eventually the opening on the piping system will get smaller and smaller and the flow of water draining will slow down or even stop

Hillman #12 - 14 x 3/4 In. Hex Washer Head Self-Drilling Sheet Metal Screw (100 Ct.) Spade Bit Set coated on both sides withHex washer head sheet metal screws. Self drilling points that drill, tap, and fasten in 1 operation. Good for attaching almost any type of material to metal. Sharp threads create their own mating thread when drilled into the material. Zinc. 100 piece pack.