We have this mounted on the roof, wired up via the 2 attached cables to a Huawei 4G ‘mi-fi’ device; which sets up a wifi hotspot inside the van. The antenna, as well as being far more powerful than the one built into the mi-fi device (or our phones) is also mounted outside of the giant metal Farady cage  which is the van. On a good day we seem to be able to get a good 15-20Mbps speed up and down.

This antenna is pretty good, and easy to fit. My only quibble is that the cables are only 50cm long, which doesn’t give you much leeway when mounting it to the mi-fi device. We also needed to buy 2 SMA-to-TS9 adapters.

£125 from Solwise.