5GB dongle allows you to surf the Internet for up to 5GB of data. Most people would choose to subscribe to 5GB dongle because they go online often, or simply because they have no idea how much data they need every month.
5GB is in the middle of a selection between 1GB, 3GB, 5GB, 7GB and 10GB and therefore it is the best choice for anyone who is new to mobile broadband
Three is offering 5GB dongle deals at £15 a month. T Mobile on the other hand is offering 5GB dongle at £30 a month.