The Panasonic PC -NLF04S WhisperLine Installation Kit allows you to install your Panasonic FV-10NLF1 Whisperline 120 CFM fans easily and simply. This single-pick up kit features a 4-inch single inlet grille, back draft damper, clamp, and zip ties. A premium ventilation fan can be cut short with improper ducting and low quality accessories. With industry standard accessories featured in the PC-NLF04S, you'll be able to utilize the full potential of your premium Panasonic FV-10NLF1. All these great qualities are backed by Panasonic's standard 3-year manufacturer's warranty.