Based on this product's specifications, here are some alternatives and similar models
Shower stool ActionMed KP100AM rectangular height-adjustable seat, aluminium frame, 35–53 cm height, 49×29 cm seat, 110 kg max
Summary description:
A rectangular shower stool ActionMed KP100AM with an aluminium frame and height-adjustable seat (35–53 cm). Seat size is 49×29 cm; maximum user weight 110 kg. Features non-slip feet, two ergonomic handrails, four legs and a lightweight 2.2 kg construction. Easy to clean and safe for shower use; not for use on slippery surfaces without protection.