|FIREBLOK's Universal Firestop Insert is intumescent thermoplastic pad used as a membrane penetration fire stop in electrical boxes maintaining the fire-resistant ratings of wall assemblies and when the horizontal separation between metallic boxes on opposite sides of the wall is less than 24” apart. The insert is certified for both 1 & 2 hour, U300, U400, V400 and U411 wall assemblies with metal electrical boxes with plastic or metal cover plates. UFSI can be used in different box sizes from single gang boxes, 4” Square boxes to 4-11/16” Square boxes.|
- 3-3/4" x 3-3/4" x 3/8"
|Metal Box Size:|
|1-Gang Box: Use half insert for max 2-1/8" x 4" x 2-1/8" in deep 1-Gang box, adheres into back of box|
|4S Box: Use one insert for max 4" x 4" x 2-1/8" in deep 4S box, adheres into back of box|
|5S Box: Use one and a half insert for max 4-11/16" x 4-11/16" x 2-1/8" in deep 5S box, one covering the inside back of the box and half insert on an internal side of the box|