Need help for RBR50 expansion options

[m_chop]

I have The RBK50 which is a kit that containing one RBR50 router and one RBS50 satellite. Can I:

1. Expand this system with an add on?
2. If so, what is the model and number I need to buy to add to this mesh?

Thanks

MC

[FURRYe38]

Can add up to 3 officially. Others reporting having 6 satellites. 

RBS50 satellites is what you would need. 

[randomousity]

Any of the RBS or RBW models should work. Basically, anything under "satellites" on this page (also pictured below).