GPS time for NTP: Any recommended devices?

[inslee]

I'm looking to use the GPS NTP server feature in OPNSense and I have an available RS232 (serial) port on my Qotom device but I'm not sure where to look to find a GPS receiver that will be compatible and also have a serial port.

Are there any ones that you've used that you know are compatible with OPNsense and have been performing well?