Based on this product's specifications, here are some alternatives and similar models
Loopback adapter DeLOCK RS-232/422/485 DB25 female
Summary description:
The DeLOCK RS-232/422/485 Loopback adapter features a DB25 female connector, designed for reliable communication testing. With dimensions of 12.6 mm width, 53.3 mm depth, and 11.8 mm height, it is compact and easy to handle. The adapter is packaged in a polybag and is made in Taiwan, ensuring quality and durability. Ideal for professionals needing to test serial connections.