Based on this product's specifications, here are some alternatives and similar models
Graduated Neutral Density Filter B&W Master Line 712 GND 0.6 (67mm)
Summary description:
B&W Master Line 712 graduated neutral density (GND 0.6) filter in 67mm size reduces light by two stops with a gradual transition. Designed for landscape and architectural photography, it balances sky and foreground exposure, helps retain highlights and detail, and enables longer exposures without overexposure. Fits lenses with 67mm thread.