That is a Global Invacom fibre to RF Gateway.
It's used in fibre optic distribution of DSTV. Meaning that if you are in an estate, there is one main dish that feeds DSTV via fibre to all the residences in the estate. So instead of having to mount your own dish, you just plug the decoder into the coax port of the gateway.
That looks like an older version, so i'm not sure it would work with an Explora decoder. You would need a multiswitch to use it with an explora anyway.