B+W 72mm XS-Pro Digital ND Vario MRC-Nano Filter 66-1075251 B&H
NiSi 72mm Nano IR Neutral Density Filter ND1000 (3.0) 10 Stop - Jim Patterson Photography
Amazon.com : NiSi 72mm Swift True Color ND-Vario - Variable Neutral Density Filter 1-5 Stops (ND2-ND32) - Rotating Adjustable ND, Compatible with NiSi Swift System Filters - Optical Glass, Waterproof Nano Coating : Electronics
HOYA 72MM HD MK-II IRND 64 ND FILTER (6-STOP)
Irix Edge Vari ND 2-5 filter 72mm | Official Irix brand store