Houdini Arnold “Standard Surface” node. 
It has inputs for specular as follows: 
* Specular - Influences brightness of spec
* Specular color - defines color of specularity
* Specular roughness - controlls glosines / roughness of the mesh
* Specular IOR
* Specular Anistropy
* Specular rotatation

In my case i have one spec map that dictates over all object specularity (i use specular_roughness to dictate that specularity. 
But i now need to plug in also secondary specular map for lips and one for oili areas of model. 
So that is 2 extra specularity maps. 
But i have no clue how to connect the secondary map and have separate controls for roughness and specularity for it. 
Can someone assist what node to use?
Also having other issue when trying to increase iterations. I get gray renders.