Can I combine the Helico together?

You can combine the Helico MK3 in whichever way you want. Pair the lightweight, soft-touch feel of nylon with the solid weight of brass, or mix stainless steel with titanium to stand apart from the silver finishes. However you build your set, Helico lets you create a variety of metallic colour combinations. 

*Helico MK3 can't be used with Helico MK2.