Based on this product's specifications, here are some alternatives and similar models
Neutral Density (ND) Variable Fader Filter K&F Type FADER for Phone Clip – ND2 to ND400
Summary description:
Variable neutral density (ND) fader filter by K&F, designed for use with phone clip mounts. Provides adjustable light reduction from ND2 to ND400, allowing control over exposure and motion blur in bright conditions. Suitable for mobile photography and videography to achieve longer exposures, smoother motion and balanced highlights without changing aperture. Compact solution for creative control on smartphones.