12 VX3918 Type Nutone Broan Central Vacuum Cleaner Bags 6 Gallons Model# VX550 VX1000, VX475, VX3918, VX3916, 784891776717 $42.25
Broan-NuTone VX3918STD Bag Standard Filter Media Bags for VX550 and VX1000 Series, 8-Gallon, 3-Pack $19.30
Broan-Nutone VX3918STD Standard Filter Media bags for VX550 and VX1000 Series (three bags per pack) $22.55