Freewell 72mm Threaded Hard Stop Variable ND Filter All Day 2 to 5 Stop & 6 to 9 Stop - 2Pack
NiSi 72mm 5-9 Stops Enhanced Variable ND Filter
Amazon.com : K&F Concept 72mm Variable ND Filter ND2-ND32 Camera Lens Filter (1-5 Stops) No X Cross HD Neutral Density Filter with 28 Multi-Layer Coatings Waterproof (Nano-X Series) : Electronics
Hoya Variable Neutral Density Filter - 72mm — Glazer's Camera
Tiffen 72mm Variable Neutral Density Filter 72VND B&H Photo Video