WiFi Extender for Three 4G Router (Sercomm LTE2122GR)

[ChrisBradshaw]

Can someone please recommend a Wifi extender that can be used with the Three 4G router (Sercomm LTE2122GR).

Ideally I would like to have two extenders (one upstairs and the other in the kitchen), but failing that one will do.

Many thanks. Chris