Based on this product's specifications, here are some alternatives and similar models
Mixer for gypsum Proline 5410115 — paddle 8×53 cm, speed 200–500 rpm
Summary description:
Handheld mixer for gypsum Proline 5410115 with a paddle measuring 8×53 cm and adjustable speed range 200–500 rpm. Designed for mixing gypsum, plaster and similar mortars, it provides consistent homogeneity and reduced air entrapment. Suitable for construction and renovation tasks, small to medium batches, and use with drill or dedicated drive that fits the paddle mounting.