Based on this product's specifications, here are some alternatives and similar models
Silicone Case Coolgadet for HMD Pulse / Pulse Pro / Pulse+ — Matte Black Backcover
Summary description:
Soft silicone protective case by Coolgadet designed for HMD Pulse, Pulse Pro and Pulse+. Matte black backcover provides scratch and minor shock protection while preserving access to ports, buttons and camera cutouts. Thin, form-fitting design adds grip and prevents slips, suitable for everyday use and commuting to protect the smartphone exterior.