These belts are for NV500 Series Rotator Vacuums, Compatible with Models : NV500, NV501, NV501C, NV502, NV503, NV500W, NV500W_31, NV505, NV520, NV520Q, NV520QPR, NV520QR, NV550, NV552, NV581 Series. If you are not sure if the is the correct belt for your model please message me with your model number.