Review on 📶 Proxicast 3G / 4G / LTE 3.5 dBi Omni-Directional Adhesive Mount Antenna (2-Pack for MIMO) - Enhances Connectivity for Cisco, Cradlepoint, Digi, MoFi, Pepwave, Sierra Wireless, Proxicast, Sixnet/Red Lion, and More by Patrick Burton

I was planning to install a Huawei e8372h LTE modem in the car. Knowing it would be hidden under the dash I bought these to fit in the A-pillars to improve the signal. Testing the e8372h indoors, in the garage, on the street, and in the car, with and without the antennas attached, the Signal and Speedtest.net results were better WITHOUT. In fact, in all scenarios with the antennas attached, the modem failed to connect at all and frequently disconnected. Without an antenna, the device also gets a pretty good signal and transmission speed in the dashboard behind the head unit. So it's not just a waste. They can even make you feel worse.