The Panasonic PC-NLF04D WhisperLine Installation Kit - 4"" Double Inlet (Double Pick Up) Panasonic WhisperLine Model: PC-NLF04D Accessory Kit Model: PC-NLF04D Type Grille: 4"" Double Inlet Inlet Grille: 2 (4"") Backdraft Damper: 2 (4"") Clamp: 12 Y-Adaptor: 1 (4"" - 4"" x 2) Zip Ties: 12 For Panasonic WhisperLine In-line fans"