Based on this product's specifications, here are some alternatives and similar models
Camera variable neutral density filter K&F Concept Nano-X 49 mm (KF01.1447)
Summary description:
K&F Concept Nano-X variable neutral density camera filter, 49 mm thread size, one piece per pack in black finish. The filter provides adjustable light reduction for long-exposure, motion blur, and aperture control in bright conditions. Fits lenses with 49 mm filter thread and is suitable for landscape, architecture and video shooting.