@anonzoblartn
The Cosy (and Flexy) use a 50 Ohms antenna with an RP-SMA female connector so any antenna compatible with that should work, but results will vary depending on distance and environmental factors. Here are two examples of higher gain antennas that may improve range:
5dBi:
9dBi (keep in mind this one is about 15 inches long it looks like):
https://www.amazon.com/dp/B00NV807XS/ref=psdc_3015438011_t1_B00TZSH5XI