Based on this product's specifications, here are some alternatives and similar models
Polax polyurethane sanding block 140×280 mm model 200-003
Summary description:
Polyurethane sanding block Polax model 200-003 sized 140×280 mm. Designed to hold abrasive paper for manual sanding tasks on wood, metal, plaster and painted surfaces. Durable polyurethane body provides consistent pressure distribution, comfortable grip and resistance to solvents. Suitable for finishing, leveling and preparing surfaces prior to painting or coating.