STI NEZDP433 Smoke and Acoustic Pathway Device 20 in Blue

STI NEZDP433 Firestop Pathway

The STI NEZDP433 is a blue smoke and acoustic pathway device designed for firestop applications in commercial and institutional buildings. It provides a sealed penetration pathway that limits the spread of smoke and sound through rated wall and floor assemblies. The unit combines steel and thermoplastic construction for durability in demanding environments. This product is supplied as a pack containing four devices and four gang plates.

For firestop contractors and facility managers

Installers sealing conduit or cable penetrations in fire-rated barriers will find this pathway device matches the specified L-ratings for smoke and acoustical performance. The 20-inch width accommodates larger bundle requirements where standard sleeves are insufficient. Projects requiring a published fire-resistance rating (F-rating or T-rating) should verify the "Not Rated Fire Rating" designation against the local code requirements before specifying this model.

20-inch width pathway device

The critical dimension for this part is the 20-inch width of the pathway opening. This measurement determines the maximum capacity for cable bundles or conduit groups passing through the firestop seal. The device installs in a square opening measuring four inches by four-and-a-half inches. Confirm that the penetration opening and the intended cable fill align with this specific width and the tested L-ratings for smoke and sound attenuation.