The Premier Pemko Acoustic Automatic Door Bottom Superior performance and an enhanced design. The Pemko STC411™ and STC4131™ automatic door bottoms are the latest design for high quality performance in acoustic control and sound attenuation. The newly designed spring assembly increases the pressure applied on the drop bar across the entire length of the automatic door bottom, maximizing seal performance. The Pemko STC411 and PDB411 are acoustically equivalent, as determined by a third-party acoustic test lab. As such, the STC411 may be used in acoustic openings in place of the PDB411 without retesting. These automatic door bottoms are a great enhancement to the Pemko Acoustic Products portfolio. When installed, the high quality, multi-finned seal of the Pemko STC- series automatic doorbottoms conforms to slight irregularities in thresholds, sills, and most flooring materials. The sealnot only provides superior acoustic performance, but also seals the opening against wind anddebris to improve its overall energy efficiency. The expertly designed Pemko STC411™ full-mortise automatic door bottom uses the existing 411 door bottom casing enabling installation into the same mortise. This makes retrofit or newinstallations easy for installers who are already familiar with existing Pemko automatic door bottoms For more information, see attached Sell Sheet.