The short antennas are great for ADS-B, and the longer antennas work well at lower frequencies. The two mounts and 3m of RG174 cable allow you to easily mount the antenna outdoors. This is an RTL-SDR blog V4 software defined radio receiver with RTL2832U ADC chip, R828D tuner, 1PPM TCXO, SMA F connector and aluminium case with passive cooling.
eBay