I've used four of these now for different projects (all on various Android devices) and each has paired painlessly with the desired mother device. Switching between devices is easy, just by turning the switch. The only VERY MINOR downside is that the device doesn't time out after a period and if you don't turn it off before periods of inactivity, the batteries will die after a few days – the switch is on the base.
A feature just discovered that is very handy is the snapshot key on the upper right of the keyboard that allows you to take a screenshot without having to use the two-finger approach which is always a bit cumbersome.
High recommended!!!