Based on this product's specifications, here are some alternatives and similar models
USB 2.0 to 4S Serial RS-232 Ports Adapter EXSYS EX-1334V
Summary description:
The EXSYS USB 2.0 to 4S Serial RS-232 adapter provides four serial ports via USB interface. It features a reliable FTDI chipset and supports multiple protocols including TxD, RxD, RTS, CTS, DTR, DSR, DCD, and GND. Compact dimensions of 150mm x 70mm x 30mm make it easy to integrate into various setups. The package includes a USB cable for immediate use.