[TowerTalk] remote antenna switch

[Merlin-7 KI4ILB]

 I have read where a few of you have posted about a remote antenna switch that is mounted near the feed points and can switch from one antenna to another.
 What kind of power do they need? 12 volt? 110?

 I am trying to keep my Ham gear all on 12 volt so that I can run it off my solar panels and battery bank.

 Does anyone make such a monster?
 Thanks and 73s 
 Joe 
KI4ILB